[PATCH] kauditd_thread warning fix

Squash this warning:

  kernel/audit.c: In function 'kauditd_thread':
  kernel/audit.c:367: warning: no return statement in function returning non-void

We might as test kthread_should_stop(), although it's not very pointful at
present.

The code which starts this thread looks racy - the kernel could start multiple
threads.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>