net: ipv4: typo issue, remove erroneous semicolon

Need remove erroneous semicolon, which is found by EXTRA_CFLAGS=-W,
the related commit number: c54419321455631079c7d6e60bc732dd0c5914c5
("GRE: Refactor GRE tunneling code")

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/ip_gre.c

@@ -444,7 +444,7 @@ static netdev_tx_t ipgre_xmit(struct sk_buff *skb,
 	if (dev->header_ops) {
 		/* Need space for new headers */
 		if (skb_cow_head(skb, dev->needed_headroom -
-				      (tunnel->hlen + sizeof(struct iphdr))));
+				      (tunnel->hlen + sizeof(struct iphdr))))
 			goto free_skb;
 
 		tnl_params = (const struct iphdr *)skb->data;