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/include/net/route.h b/include/net/route.h
index 4e8cae0..40f6346 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -210,7 +210,7 @@
 
 static inline int inet_iif(const struct sk_buff *skb)
 {
-	return skb->rtable->rt_iif;
+	return skb_rtable(skb)->rt_iif;
 }
 
 #endif	/* _ROUTE_H */