bridge: memorize and export selected IGMP/MLD querier port

Adding bridge support to the batman-adv multicast optimization requires
batman-adv knowing about the existence of bridged-in IGMP/MLD queriers
to be able to reliably serve any multicast listener behind this same
bridge.

Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 50e2ab0..8346e95 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -70,6 +70,7 @@
 /* selected querier */
 struct bridge_mcast_querier {
 	struct br_ip addr;
+	struct net_bridge_port __rcu	*port;
 };
 #endif