bridge: Do not unregister all PF_BRIDGE rtnl operations

Bridge fdb and link rtnl operations are registered in
core/rtnetlink.  Bridge mdb operations are registred
in bridge/mdb.  When removing bridge module, do not
unregister ALL PF_BRIDGE ops since that would remove
the ops from rtnetlink as well.  Do remove mdb ops when
bridge is destroyed.

Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/br_mdb.c

@@ -482,3 +482,10 @@ void br_mdb_init(void)
 	rtnl_register(PF_BRIDGE, RTM_NEWMDB, br_mdb_add, NULL, NULL);
 	rtnl_register(PF_BRIDGE, RTM_DELMDB, br_mdb_del, NULL, NULL);
 }
+
+void br_mdb_uninit(void)
+{
+	rtnl_unregister(PF_BRIDGE, RTM_GETMDB);
+	rtnl_unregister(PF_BRIDGE, RTM_NEWMDB);
+	rtnl_unregister(PF_BRIDGE, RTM_DELMDB);
+}