Fix order

deps/build.jl

@@ -2,16 +2,14 @@
 # In that case, we have to do this little dance to get around having to use BinDeps
 # for a library that's already linked to Julia.
 settings = joinpath(@__DIR__, "..", ".build_settings")
-action = ""
-if isfile(settings)
-    provider = readchomp(settings)
-    action = "delete " * normpath(settings)
-elseif haskey(ENV, "JULIA_FFTW_PROVIDER")
+if haskey(ENV, "JULIA_FFTW_PROVIDER")
     provider = ENV["JULIA_FFTW_PROVIDER"]
     open(f -> println(f, provider), settings, "w")
-    action = "unset the JULIA_FFTW_PROVIDER environment variable"
+elseif isfile(settings)
+    provider = readchomp(settings)
 else
-    provider = ""
+    provider = "FFTW"
+    open(f -> println(f, provider), settings, "w")
 end
 if provider == "MKL" && Base.BLAS.vendor() === :mkl
     mklpath = Libdl.dlpath("libmkl_rt")
@@ -30,7 +28,8 @@ if provider == "MKL" && Base.BLAS.vendor() === :mkl
     end
 elseif provider == "MKL"
     error("MKL build requested for FFTW but Julia was not built with MKL.\n",
-          "To fix this, " action, " and rerun Pkg.build(\"FFTW\").")
+          "To fix this, set ENV[\"JULIA_FFTW_PROVIDER\"] = \"FFTW\" and \n",
+          "rerun Pkg.build(\"FFTW\").")
 else
     include("build_fftw.jl")
 end