bridge: Allow multicast snooping to be disabled before ifup

Currently you cannot disable multicast snooping while a device is
down.  There is no good reason for this restriction and this patch
removes it.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/bridge/br_multicast.c

@@ -1728,13 +1728,9 @@ int br_multicast_set_port_router(struct net_bridge_port *p, unsigned long val)
 int br_multicast_toggle(struct net_bridge *br, unsigned long val)
 {
 	struct net_bridge_port *port;
-	int err = -ENOENT;
+	int err = 0;
 
 	spin_lock(&br->multicast_lock);
-	if (!netif_running(br->dev))
-		goto unlock;
-
-	err = 0;
 	if (br->multicast_disabled == !val)
 		goto unlock;
 
@@ -1742,6 +1738,9 @@ int br_multicast_toggle(struct net_bridge *br, unsigned long val)
 	if (br->multicast_disabled)
 		goto unlock;
 
+	if (!netif_running(br->dev))
+		goto unlock;
+
 	if (br->mdb) {
 		if (br->mdb->old) {
 			err = -EEXIST;