bridge: Fix OOM crash in deliver_clone

The bridge multicast patches introduced an OOM crash in the forward
path, when deliver_clone fails to clone the skb.
Reported-by: Mark Wagner <mwagner@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/br_forward.c

@@ -140,10 +140,10 @@ static int deliver_clone(const struct net_bridge_port *prev,
 			 void (*__packet_hook)(const struct net_bridge_port *p,
 					       struct sk_buff *skb))
 {
-	skb = skb_clone(skb, GFP_ATOMIC);
-	if (!skb) {
 	struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
 
+	skb = skb_clone(skb, GFP_ATOMIC);
+	if (!skb) {
 		dev->stats.tx_dropped++;
 		return -ENOMEM;
 	}