bridge: fdb: converge fdb searching functions into one

Before this patch we had 3 different fdb searching functions which was
confusing. This patch reduces all of them to one - fdb_find_rcu(), and
two flavors: br_fdb_find() which requires hash_lock and br_fdb_find_rcu
which requires RCU. This makes it clear what needs to be used, we also
remove two abusers of __br_fdb_get which called it under hash_lock and
replace them with br_fdb_find().

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 1cbbf63..6136818 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -507,8 +507,9 @@ void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr);
 void br_fdb_cleanup(struct work_struct *work);
 void br_fdb_delete_by_port(struct net_bridge *br,
 			   const struct net_bridge_port *p, u16 vid, int do_all);
-struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
-					  const unsigned char *addr, __u16 vid);
+struct net_bridge_fdb_entry *br_fdb_find_rcu(struct net_bridge *br,
+					     const unsigned char *addr,
+					     __u16 vid);
 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr);
 int br_fdb_fillbuf(struct net_bridge *br, void *buf, unsigned long count,
 		   unsigned long off);