[PATCH] SELinux: convert sbsec semaphore to a mutex

This patch converts the semaphore in the superblock security struct to a
mutex.  No locking changes or other code changes are done.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>