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/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
index 8ed3c37..43fbf6b 100644
--- a/net/bluetooth/rfcomm/sock.c
+++ b/net/bluetooth/rfcomm/sock.c
@@ -503,7 +503,7 @@
 	BT_DBG("sk %p timeo %ld", sk, timeo);
 
 	/* Wait for an incoming connection. (wake-one). */
-	add_wait_queue_exclusive(sk->sk_sleep, &wait);
+	add_wait_queue_exclusive(sk_sleep(sk), &wait);
 	while (!(nsk = bt_accept_dequeue(sk, newsock))) {
 		set_current_state(TASK_INTERRUPTIBLE);
 		if (!timeo) {
@@ -526,7 +526,7 @@
 		}
 	}
 	set_current_state(TASK_RUNNING);
-	remove_wait_queue(sk->sk_sleep, &wait);
+	remove_wait_queue(sk_sleep(sk), &wait);
 
 	if (err)
 		goto done;
@@ -621,7 +621,7 @@
 {
 	DECLARE_WAITQUEUE(wait, current);
 
-	add_wait_queue(sk->sk_sleep, &wait);
+	add_wait_queue(sk_sleep(sk), &wait);
 	for (;;) {
 		set_current_state(TASK_INTERRUPTIBLE);
 
@@ -640,7 +640,7 @@
 	}
 
 	__set_current_state(TASK_RUNNING);
-	remove_wait_queue(sk->sk_sleep, &wait);
+	remove_wait_queue(sk_sleep(sk), &wait);
 	return timeo;
 }