bridge: use rx_handler_data pointer to store net_bridge_port pointer

Register net_bridge_port pointer as rx_handler data pointer. As br_port is
removed from struct net_device, another netdev priv_flag is added to indicate
the device serves as a bridge port. Also rcuized pointers are now correctly
dereferenced in br_fdb.c and in netfilter parts.

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index 2663743..6818e60 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -242,11 +242,11 @@
 	struct net_bridge_fdb_entry *fdb;
 	int ret;
 
-	if (!dev->br_port)
+	if (!br_port_exists(dev))
 		return 0;
 
 	rcu_read_lock();
-	fdb = __br_fdb_get(dev->br_port->br, addr);
+	fdb = __br_fdb_get(br_port_get_rcu(dev)->br, addr);
 	ret = fdb && fdb->dst->dev != dev &&
 		fdb->dst->state == BR_STATE_FORWARDING;
 	rcu_read_unlock();