[TCP]: Use skb_set_mac_header in tcp_collapse

Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/tcp_input.c

@@ -3633,7 +3633,7 @@ tcp_collapse(struct sock *sk, struct sk_buff_head *list,
 		if (!nskb)
 			return;
 
-		nskb->mac.raw = nskb->data + (skb->mac.raw - skb->head);
+		skb_set_mac_header(nskb, skb->mac.raw - skb->head);
 		nskb->nh.raw = nskb->data + (skb->nh.raw - skb->head);
 		nskb->h.raw = nskb->data + (skb->h.raw - skb->head);