[PATCH] SELinux: change isec semaphore to a mutex

This patch converts the remaining isec->sem into a mutex.  Very similar
locking is provided as before only in the faster smaller mutex rather than a
semaphore.  An out_unlock path is introduced rather than the conditional
unlocking found in the original code.

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>