net: skb->rtable accessor

Define skb_rtable(const struct sk_buff *skb) accessor to get rtable from skb

Delete skb->rtable field

Setting rtable is not allowed, just set dst instead as rtable is an alias.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index e6058a5..afabd27 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -948,7 +948,7 @@
 	case IGMPV2_HOST_MEMBERSHIP_REPORT:
 	case IGMPV3_HOST_MEMBERSHIP_REPORT:
 		/* Is it our report looped back? */
-		if (skb->rtable->fl.iif == 0)
+		if (skb_rtable(skb)->fl.iif == 0)
 			break;
 		/* don't rely on MC router hearing unicast reports */
 		if (skb->pkt_type == PACKET_MULTICAST ||