[ATM]: Add struct net_bridge decl to net/atm/common.c

net/atm/common.c

@@ -687,6 +687,7 @@ int vcc_getsockopt(struct socket *sock, int level, int optname,
 
 #if defined(CONFIG_ATM_LANE) || defined(CONFIG_ATM_LANE_MODULE)
 #if defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)
+struct net_bridge;
 struct net_bridge_fdb_entry *(*br_fdb_get_hook)(struct net_bridge *br,
 						unsigned char *addr) = NULL;
 void (*br_fdb_put_hook)(struct net_bridge_fdb_entry *ent) = NULL;