Fix sys_stat.mkfifo when not run as root.

It's not allowed for a shell user to create a fifo in /data/local/tmp.
Make the test do nothing if not run as root.

Bug: 17646702

(cherry picked from commit 6c69afdb6ddd56e011b59e3060f12a5bdffb5f5c)

Change-Id: Ia3a862ed4586413b7bb393557ab57e0a7141d888
1 file changed