[SK_BUFF]: Introduce igmp_hdr() & friends, remove skb->h.igmph

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 03869d9..05bc270 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -1430,7 +1430,7 @@
 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(*encap)))
 		goto drop;
 
-	pim = (struct igmphdr*)skb->h.raw;
+	pim = igmp_hdr(skb);
 
 	if (!mroute_do_pim ||
 	    skb->len < sizeof(*pim) + sizeof(*encap) ||