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/arp.c b/net/ipv4/arp.c
index f11931c..816494f 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -474,7 +474,7 @@
 		return 1;
 	}
 
-	paddr = skb->rtable->rt_gateway;
+	paddr = skb_rtable(skb)->rt_gateway;
 
 	if (arp_set_predefined(inet_addr_type(dev_net(dev), paddr), haddr, paddr, dev))
 		return 0;
@@ -817,7 +817,7 @@
 	if (arp->ar_op == htons(ARPOP_REQUEST) &&
 	    ip_route_input(skb, tip, sip, 0, dev) == 0) {
 
-		rt = skb->rtable;
+		rt = skb_rtable(skb);
 		addr_type = rt->rt_type;
 
 		if (addr_type == RTN_LOCAL) {