net: skb->dst accessors

Define three accessors to get/set dst attached to a skb

struct dst_entry *skb_dst(const struct sk_buff *skb)

void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)

void skb_dst_drop(struct sk_buff *skb)
This one should replace occurrences of :
dst_release(skb->dst)
skb->dst = NULL;

Delete skb->dst field

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
index 425e311..a0e9753 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
@@ -261,7 +261,7 @@
 
 		skb->dev = dev;
 
-		if (!skb->dst || !skb->dst->neighbour) {
+		if (!skb_dst(skb) || !skb_dst(skb)->neighbour) {
 			/* put pseudoheader back on for next time */
 			skb_push(skb, sizeof (struct ipoib_pseudoheader));
 		}
@@ -707,10 +707,10 @@
 
 out:
 	if (mcast && mcast->ah) {
-		if (skb->dst		&&
-		    skb->dst->neighbour &&
-		    !*to_ipoib_neigh(skb->dst->neighbour)) {
-			struct ipoib_neigh *neigh = ipoib_neigh_alloc(skb->dst->neighbour,
+		if (skb_dst(skb)		&&
+		    skb_dst(skb)->neighbour &&
+		    !*to_ipoib_neigh(skb_dst(skb)->neighbour)) {
+			struct ipoib_neigh *neigh = ipoib_neigh_alloc(skb_dst(skb)->neighbour,
 									skb->dev);
 
 			if (neigh) {