[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/drivers/net/ioc3-eth.c b/drivers/net/ioc3-eth.c
index ea07aa5..d375e78 100644
--- a/drivers/net/ioc3-eth.c
+++ b/drivers/net/ioc3-eth.c
@@ -1393,9 +1393,9 @@
 	 * manually.
 	 */
 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
-		int proto = ntohs(skb->nh.iph->protocol);
+		const struct iphdr *ih = ip_hdr(skb);
+		const int proto = ntohs(ih->protocol);
 		unsigned int csoff;
-		struct iphdr *ih = skb->nh.iph;
 		uint32_t csum, ehsum;
 		uint16_t *eh;