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_stp_bpdu.c b/net/bridge/br_stp_bpdu.c
index 217bd22..70aecb4 100644
--- a/net/bridge/br_stp_bpdu.c
+++ b/net/bridge/br_stp_bpdu.c
@@ -137,12 +137,13 @@
 		struct net_device *dev)
 {
 	const unsigned char *dest = eth_hdr(skb)->h_dest;
-	struct net_bridge_port *p = rcu_dereference(dev->br_port);
+	struct net_bridge_port *p;
 	struct net_bridge *br;
 	const unsigned char *buf;
 
-	if (!p)
+	if (!br_port_exists(dev))
 		goto err;
+	p = br_port_get_rcu(dev);
 
 	if (!pskb_may_pull(skb, 4))
 		goto err;