ipc,msg: drop msg_unlock

There is only one user left, drop this function and just call
ipc_unlock_object() and rcu_read_unlock().

Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/ipc/msg.c b/ipc/msg.c
index 8203e71..b0d541d4 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -70,8 +70,6 @@
 
 #define msg_ids(ns)	((ns)->ids[IPC_MSG_IDS])
 
-#define msg_unlock(msq)		ipc_unlock(&(msq)->q_perm)
-
 static void freeque(struct ipc_namespace *, struct kern_ipc_perm *);
 static int newque(struct ipc_namespace *, struct ipc_params *);
 #ifdef CONFIG_PROC_FS
@@ -270,7 +268,8 @@
 	expunge_all(msq, -EIDRM);
 	ss_wakeup(&msq->q_senders, 1);
 	msg_rmid(ns, msq);
-	msg_unlock(msq);
+	ipc_unlock_object(&msq->q_perm);
+	rcu_read_unlock();
 
 	list_for_each_entry_safe(msg, t, &msq->q_messages, m_list) {
 		atomic_dec(&ns->msg_hdrs);