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/rose/af_rose.c b/net/rose/af_rose.c
index 4fb711a..8e45e76 100644
--- a/net/rose/af_rose.c
+++ b/net/rose/af_rose.c
@@ -845,7 +845,7 @@
 		DEFINE_WAIT(wait);
 
 		for (;;) {
-			prepare_to_wait(sk->sk_sleep, &wait,
+			prepare_to_wait(sk_sleep(sk), &wait,
 					TASK_INTERRUPTIBLE);
 			if (sk->sk_state != TCP_SYN_SENT)
 				break;
@@ -858,7 +858,7 @@
 			err = -ERESTARTSYS;
 			break;
 		}
-		finish_wait(sk->sk_sleep, &wait);
+		finish_wait(sk_sleep(sk), &wait);
 
 		if (err)
 			goto out_release;
@@ -911,7 +911,7 @@
 	 *	hooked into the SABM we saved
 	 */
 	for (;;) {
-		prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
+		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 
 		skb = skb_dequeue(&sk->sk_receive_queue);
 		if (skb)
@@ -930,7 +930,7 @@
 		err = -ERESTARTSYS;
 		break;
 	}
-	finish_wait(sk->sk_sleep, &wait);
+	finish_wait(sk_sleep(sk), &wait);
 	if (err)
 		goto out_release;