tipc: Optimize pointer dereferencing when receiving stream data

This patch eliminates an unnecessary pointer dereference when
accessing a stream-based socket's receive queue.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/socket.c

@@ -1133,7 +1133,7 @@ restart:
 	/* Loop around if more data is required */
 
 	if ((sz_copied < buf_len)    /* didn't get all requested data */
-	    && (!skb_queue_empty(&sock->sk->sk_receive_queue) ||
+	    && (!skb_queue_empty(&sk->sk_receive_queue) ||
 		(flags & MSG_WAITALL))
 				     /* ... and more is ready or required */
 	    && (!(flags & MSG_PEEK)) /* ... and aren't just peeking at data */