Fix some gosimple issues

See,
$ golangci-lint run --disable-all --enable=gosimple
govc/cluster/rule/ls.go:80:23: S1025: the argument is already a string, there's no need to use fmt.Sprintf (gosimple)
                                res = append(res, fmt.Sprintf("%s", ruleName))
                                                  ^
govc/dvs/portgroup/info.go:105:10: S1034: assigning the result of this type assertion to a variable (switch port := port.(type)) could eliminate the following type assertions:

        govc/dvs/portgroup/info.go:109:78 (gosimple)
                switch port.(type) {
                       ^
govc/dvs/portgroup/info.go:119:11: S1025: the argument is already a string, there's no need to use fmt.Sprintf (gosimple)
                        return fmt.Sprintf("%s", address.(*types.SingleIp).Address)
                               ^
govc/vm/info.go:105:3: S1020: when ok is true, err can't be nil (gosimple)
                if _, ok := err.(*find.NotFoundError); ok {
                ^
govc/vm/network/add.go:77:11: S1028: should use fmt.Errorf(...) instead of errors.New(fmt.Sprintf(...)) (gosimple)
                        return errors.New(fmt.Sprintf("couldn't set specified network %v",
                               ^
govc/vm/network/change.go:90:11: S1028: should use fmt.Errorf(...) instead of errors.New(fmt.Sprintf(...)) (gosimple)
                        return errors.New(fmt.Sprintf("couldn't set specified network %v",
                               ^
object/diagnostic_manager.go:74:2: S1031: unnecessary nil check around range (gosimple)
        if host != nil {
        ^
simulator/host_datastore_browser.go:131:5: S1008: should use 'return <expr>' instead of 'if <expr> { return <bool> }; return <bool>' (gosimple)
                                if strings.HasSuffix(name, "-flat.vmdk") {
                                ^
test/functional/helper.go:118:30: S1002: should omit comparison to bool constant, can be simplified to `*i.Vmfs.Local` (gosimple)
                        if i.Vmfs.Local != nil && *i.Vmfs.Local == true {
                                                  ^
toolbox/process_test.go:229:2: S1021: should merge variable declaration with assignment on next line (gosimple)
        var err error
        ^
toolbox/vix/protocol.go:819:46: S1030: should use buf.String() instead of string(buf.Bytes()) (gosimple)
        str, err := base64.StdEncoding.DecodeString(string(buf.Bytes()))
                                                    ^
units/size_test.go:35:12: S1025: should use String() instead of fmt.Sprintf (gosimple)
        actual := fmt.Sprintf("%s", b)
                  ^
vapi/library/finder/finder.go:74:2: S1017: should replace this `if` statement with an unconditional `strings.TrimPrefix` (gosimple)
        if strings.HasPrefix(ipath, "/") {
        ^

govc/cluster/rule/ls.go

@@ -77,7 +77,7 @@ func (cmd *ls) Run(ctx context.Context, f *flag.FlagSet) error {
 				ruleTypeInfo := GetExtendedClusterRuleInfo(g).ruleType
 				res = append(res, fmt.Sprintf("%s (%s)", ruleName, ruleTypeInfo))
 			} else {
-				res = append(res, fmt.Sprintf("%s", ruleName))
+				res = append(res, ruleName)
 			}
 		}
 	} else {

govc/dvs/portgroup/info.go

@@ -102,11 +102,12 @@ type infoResult struct {
 
 func printPort(port types.BaseDvsIpPort) string {
 	if port != nil {
-		switch port.(type) {
+		switch portType := port.(type) {
 		case *types.DvsSingleIpPort:
-			return fmt.Sprintf("%d", port.(*types.DvsSingleIpPort).PortNumber)
+			return fmt.Sprintf("%d", portType.PortNumber)
 		case *types.DvsIpPortRange:
-			return fmt.Sprintf("%d-%d", port.(*types.DvsIpPortRange).StartPortNumber, port.(*types.DvsIpPortRange).EndPortNumber)
+			return fmt.Sprintf("%d-%d", portType.StartPortNumber,
+				portType.EndPortNumber)
 		}
 	}
 	return "Any"
@@ -116,7 +117,7 @@ func printAddress(address types.BaseIpAddress) string {
 	if address != nil {
 		switch (address).(type) {
 		case *types.SingleIp:
-			return fmt.Sprintf("%s", address.(*types.SingleIp).Address)
+			return address.(*types.SingleIp).Address
 		case *types.IpRange:
 			return fmt.Sprintf("%s/%d", address.(*types.IpRange).AddressPrefix, address.(*types.IpRange).PrefixLength)
 		}

govc/object/collect.go

@@ -413,7 +413,6 @@ func (cmd *collect) Run(ctx context.Context, f *flag.FlagSet) error {
 				if matches > 0 {
 					return true
 				}
-
 				return false
 			}
 

govc/vm/network/add.go

@@ -74,8 +74,8 @@ func (cmd *add) Run(ctx context.Context, f *flag.FlagSet) error {
 	if f.NArg() > 0 {
 		err = cmd.NetworkFlag.Set(f.Arg(0))
 		if err != nil {
-			return errors.New(fmt.Sprintf("couldn't set specified network %v",
-				err))
+			return fmt.Errorf("couldn't set specified network %v",
+				err)
 		}
 	}
 

govc/vm/network/change.go

@@ -87,8 +87,8 @@ func (cmd *change) Run(ctx context.Context, f *flag.FlagSet) error {
 	if f.NArg() > 1 {
 		err = cmd.NetworkFlag.Set(f.Arg(1))
 		if err != nil {
-			return errors.New(fmt.Sprintf("couldn't set specified network %v",
-				err))
+			return fmt.Errorf("couldn't set specified network %v",
+				err)
 		}
 	}
 

object/diagnostic_manager.go

@@ -71,10 +71,8 @@ func (m DiagnosticManager) GenerateLogBundles(ctx context.Context, includeDefaul
 		IncludeDefault: includeDefault,
 	}
 
-	if host != nil {
-		for _, h := range host {
-			req.Host = append(req.Host, h.Reference())
-		}
+	for _, h := range host {
+		req.Host = append(req.Host, h.Reference())
 	}
 
 	res, err := methods.GenerateLogBundles_Task(ctx, m.c, &req)

simulator/host_datastore_browser.go

@@ -128,12 +128,13 @@ func (s *searchDatastore) queryMatch(file os.FileInfo) bool {
 			}
 		case *types.VmDiskFileQuery:
 			if ext == ".vmdk" {
-				if strings.HasSuffix(name, "-flat.vmdk") {
-					// only matches the descriptor, not the backing file(s)
-					return false
-				}
+				// if strings.HasSuffix(name, "-flat.vmdk") {
+				//	// only matches the descriptor, not the backing file(s)
+				//	return false
+				//}
 				// TODO: check Filter and Details fields
-				return true
+				//return true
+				return !strings.HasSuffix(name, "-flat.vmdk")
 			}
 		case *types.VmLogFileQuery:
 			if ext == ".log" {

test/functional/helper.go

@@ -115,7 +115,7 @@ func (h *Helper) LocalDatastores(ctx context.Context, cr *object.ComputeResource
 
 		switch i := mds.Info.(type) {
 		case *types.VmfsDatastoreInfo:
-			if i.Vmfs.Local != nil && *i.Vmfs.Local == true {
+			if i.Vmfs.Local != nil && *i.Vmfs.Local {
 				break
 			}
 		default:

toolbox/process_test.go

@@ -226,9 +226,7 @@ func TestEscapeXML(t *testing.T) {
 
 func TestProcessError(t *testing.T) {
 	fault := errors.New("fail")
-	var err error
-
-	err = &ProcessError{Err: fault}
+	var err error = &ProcessError{Err: fault}
 
 	if err.Error() != fault.Error() {
 		t.Fatal()

toolbox/vix/protocol.go

@@ -816,7 +816,7 @@ func (c *UserCredentialNamePassword) UnmarshalBinary(data []byte) error {
 		return err
 	}
 
-	str, err := base64.StdEncoding.DecodeString(string(buf.Bytes()))
+	str, err := base64.StdEncoding.DecodeString(buf.String())
 	if err != nil {
 		return err
 	}

units/size_test.go

@@ -17,7 +17,6 @@ limitations under the License.
 package units
 
 import (
-	"fmt"
 	"math"
 	"testing"
 )
@@ -31,8 +30,7 @@ func TestMB(t *testing.T) {
 }
 
 func TestTenMB(t *testing.T) {
-	b := ByteSize(10 * 1024 * 1024)
-	actual := fmt.Sprintf("%s", b)
+	actual := ByteSize(10 * 1024 * 1024).String()
 	expected := "10.0MB"
 	if actual != expected {
 		t.Errorf("Expected '%v' but got '%v'", expected, actual)

vapi/library/finder/finder.go

@@ -71,9 +71,7 @@ func (f *Finder) find(ctx context.Context, ipath string) ([]FindResult, error) {
 	}
 
 	// Get the argument and remove any leading separator characters.
-	if strings.HasPrefix(ipath, "/") {
-		ipath = ipath[1:]
-	}
+	ipath = strings.TrimPrefix(ipath, "/")
 
 	// Tokenize the path into its distinct parts.
 	parts := strings.Split(ipath, "/")