Improve -Z error reporting.

The most likely reason for setfscreatecon to fail is that you don't have permission, and that's reported by the write return EACCES. There isn't really a "bad" context; they're just strings.

Before:

  $ adb shell mkdir -Z x y
  mkdir: bad -Z 'x'

After:

  $ adb shell mkdir -Z x y
  mkdir: -Z 'x' failed: Permission denied

Other than this, the ToT mkdir works fine with SELinux.

3 files changed, 3 insertions, 3 deletions

diff --git a/toys/lsb/mknod.c b/toys/lsb/mknod.c
index d6cd65ce..39073fad 100644
--- a/toys/lsb/mknod.c
+++ b/toys/lsb/mknod.c
@@ -52,7 +52,7 @@ void mknod_main(void)
 
   if (toys.optflags & FLAG_Z)
     if (-1 == lsm_set_create(TT.arg_context))
-      error_exit("bad -Z '%s'", TT.arg_context);
+      perror_exit("-Z '%s' failed", TT.arg_context);
   if (mknod(*toys.optargs, mode|modes[type], makedev(major, minor)))
     perror_exit("%s", *toys.optargs);
 }
diff --git a/toys/posix/mkdir.c b/toys/posix/mkdir.c
index 438e38ea..95bdf333 100644
--- a/toys/posix/mkdir.c
+++ b/toys/posix/mkdir.c
@@ -43,7 +43,7 @@ void mkdir_main(void)
 
   if (CFG_MKDIR_Z && (toys.optflags&FLAG_Z))
     if (0>lsm_set_create(TT.arg_context))
-      error_exit("bad -Z '%s'", TT.arg_context);
+      perror_exit("-Z '%s' failed", TT.arg_context);
 
   if (TT.arg_mode) mode = string_to_mode(TT.arg_mode, 0777);
 
diff --git a/toys/posix/mkfifo.c b/toys/posix/mkfifo.c
index 7bc43cce..9aa3a3ae 100644
--- a/toys/posix/mkfifo.c
+++ b/toys/posix/mkfifo.c
@@ -43,7 +43,7 @@ void mkfifo_main(void)
 
   if (CFG_MKFIFO_Z && (toys.optflags&FLAG_Z))
     if (0>lsm_set_create(TT.Z))
-      error_exit("bad -Z '%s'", TT.Z);
+      perror_exit("-Z '%s' failed", TT.Z);
 
   for (s = toys.optargs; *s; s++)
     if (mknod(*s, S_IFIFO | TT.mode, 0) < 0) perror_msg("%s", *s);