[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/spider_net.c b/drivers/net/spider_net.c
index f7e0ac7..230da14 100644
--- a/drivers/net/spider_net.c
+++ b/drivers/net/spider_net.c
@@ -720,7 +720,7 @@
 	spin_unlock_irqrestore(&chain->lock, flags);
 
 	if (skb->protocol == htons(ETH_P_IP) && skb->ip_summed == CHECKSUM_PARTIAL)
-		switch (skb->nh.iph->protocol) {
+		switch (ip_hdr(skb)->protocol) {
 		case IPPROTO_TCP:
 			hwdescr->dmac_cmd_status |= SPIDER_NET_DMAC_TCP;
 			break;