keys: remove unused key_alloc_sem

This semaphore doesn't appear to be used, so remove it.
Signed-off-by: Daniel Walker <dwalker@mvista.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

security/keys/internal.h

@@ -78,7 +78,6 @@ extern unsigned key_quota_maxbytes;
 
 extern struct rb_root key_serial_tree;
 extern spinlock_t key_serial_lock;
-extern struct semaphore key_alloc_sem;
 extern struct mutex key_construction_mutex;
 extern wait_queue_head_t request_key_conswq;