[SK_BUFF]: Introduce ip_hdr(), remove skb->nh.iph

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/inet_ecn.h b/include/net/inet_ecn.h
index b9ed389..6fd4452 100644
--- a/include/net/inet_ecn.h
+++ b/include/net/inet_ecn.h
@@ -116,7 +116,7 @@
 	case __constant_htons(ETH_P_IP):
 		if (skb_network_header(skb) + sizeof(struct iphdr) <=
 		    skb->tail)
-			return IP_ECN_set_ce(skb->nh.iph);
+			return IP_ECN_set_ce(ip_hdr(skb));
 		break;
 
 	case __constant_htons(ETH_P_IPV6):