net: sk_sleep() helper

Define a new function to return the waitqueue of a "struct sock".

static inline wait_queue_head_t *sk_sleep(struct sock *sk)
{
	return sk->sk_sleep;
}

Change all read occurrences of sk_sleep by a call to this function.

Needed for a future RCU conversion. sk_sleep wont be a field directly
available.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bluetooth/bnep/core.c b/net/bluetooth/bnep/core.c
index 8062dad..f10b41f 100644
--- a/net/bluetooth/bnep/core.c
+++ b/net/bluetooth/bnep/core.c
@@ -474,7 +474,7 @@
 	set_user_nice(current, -15);
 
 	init_waitqueue_entry(&wait, current);
-	add_wait_queue(sk->sk_sleep, &wait);
+	add_wait_queue(sk_sleep(sk), &wait);
 	while (!atomic_read(&s->killed)) {
 		set_current_state(TASK_INTERRUPTIBLE);
 
@@ -496,7 +496,7 @@
 		schedule();
 	}
 	set_current_state(TASK_RUNNING);
-	remove_wait_queue(sk->sk_sleep, &wait);
+	remove_wait_queue(sk_sleep(sk), &wait);
 
 	/* Cleanup session */
 	down_write(&bnep_session_sem);
@@ -507,7 +507,7 @@
 	/* Wakeup user-space polling for socket errors */
 	s->sock->sk->sk_err = EUNATCH;
 
-	wake_up_interruptible(s->sock->sk->sk_sleep);
+	wake_up_interruptible(sk_sleep(s->sock->sk));
 
 	/* Release the socket */
 	fput(s->sock->file);
@@ -638,7 +638,7 @@
 
 		/* Kill session thread */
 		atomic_inc(&s->killed);
-		wake_up_interruptible(s->sock->sk->sk_sleep);
+		wake_up_interruptible(sk_sleep(s->sock->sk));
 	} else
 		err = -ENOENT;