net: Fix typo in net/core/sock.c.

In sock_queue_rcv_skb()  (net/core/sock.c) it should be:
"Cast sk->rcvbuf ..." instead of: "Cast skb->rcvbuf ..."
Signed-off-by: Rami Rosen <ramirose@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/sock.c

@@ -270,7 +270,7 @@ int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 	int err = 0;
 	int skb_len;
 
-	/* Cast skb->rcvbuf to unsigned... It's pointless, but reduces
+	/* Cast sk->rcvbuf to unsigned... It's pointless, but reduces
 	   number of warnings when compiling with -W --ANK
 	 */
 	if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=