apparmor: fix incorrect usage of sizeof on char ptr

In criu/apparmor.c: write_aa_policy(), the arg path is passed as a char
pointer. The original code used sizeof(path) to get the size of it,
which is incorrect as it always return the size of the char pointer
(typically 8 or 4), not the actual capacity of the char array.

Given that this function is only invoked with path declared as `char
path[PATH_MAX]`, replacing sizeof(path) with PATH_MAX should correctly
represent the maximum size of it.

Fixes: 8723e3f ("check: add a feature test for apparmor_stacking")

Signed-off-by: Haorong Lu <[email protected]>

criu/apparmor.c

@@ -551,8 +551,8 @@ static int write_aa_policy(AaNamespace *ns, char *path, int offset, char *rewrit
 			goto fail;
 	}
 
-	ret = snprintf(path + offset + my_offset, sizeof(path) - offset - my_offset, "/.replace");
-	if (ret < 0 || ret >= sizeof(path) - offset - my_offset) {
+	ret = snprintf(path + offset + my_offset, PATH_MAX - offset - my_offset, "/.replace");
+	if (ret < 0 || ret >= PATH_MAX - offset - my_offset) {
 		pr_err("snprintf failed\n");
 		goto fail;
 	}