macvlan: Move skb_clone check closer to call

Currently macvlan calls skb_clone in macvlan_broadcast but checks
for a NULL return in macvlan_broadcast_one instead.  This is
needlessly confusing and may lead to bugs introduced later.

This patch moves the error check to where the skb_clone call is.

The only other caller of macvlan_broadcast_one never passes in a
NULL value so it doesn't need the check either.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Thanks,
Reviewed-by: NSimon Horman <horms@verge.net.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/macvlan.c

@@ -118,8 +118,6 @@ static int macvlan_broadcast_one(struct sk_buff *skb,
 				 const struct ethhdr *eth, bool local)
 {
 	struct net_device *dev = vlan->dev;
-	if (!skb)
-		return NET_RX_DROP;
 
 	if (local)
 		return vlan->forward(dev, skb);
@@ -171,9 +169,13 @@ static void macvlan_broadcast(struct sk_buff *skb,
 			hash = mc_hash(vlan, eth->h_dest);
 			if (!test_bit(hash, vlan->mc_filter))
 				continue;
+
+			err = NET_RX_DROP;
 			nskb = skb_clone(skb, GFP_ATOMIC);
-			err = macvlan_broadcast_one(nskb, vlan, eth,
-					 mode == MACVLAN_MODE_BRIDGE);
+			if (likely(nskb))
+				err = macvlan_broadcast_one(
+					nskb, vlan, eth,
+					mode == MACVLAN_MODE_BRIDGE);
 			macvlan_count_rx(vlan, skb->len + ETH_HLEN,
 					 err == NET_RX_SUCCESS, 1);
 		}