driver: macvlan: Check if need rollback multicast setting in macvlan_open

When dev_set_promiscuity failed in macvlan_open, it always invokes
dev_set_allmulti without checking if necessary.
Now check the IFF_ALLMULTI flag firstly before rollback the multicast
setting in the error handler.
Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/macvlan.c

@@ -623,6 +623,7 @@ static int macvlan_open(struct net_device *dev)
 	return 0;
 
 clear_multi:
+	if (dev->flags & IFF_ALLMULTI)
 		dev_set_allmulti(lowerdev, -1);
 del_unicast:
 	dev_uc_del(lowerdev, dev->dev_addr);