[TCP]: Trivial tcp_data_queue() cleanup

This patch removes a superfluous intialization from tcp_data_queue().
Signed-off-by: NJames Morris <jmorris@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/tcp_input.c

@@ -3517,7 +3517,6 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
 	if (TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq)
 		goto drop;
 
-	th = skb->h.th;
 	__skb_pull(skb, th->doff*4);
 
 	TCP_ECN_accept_cwr(tp, skb);