net: bridge: fdb: avoid two atomic bitops in br_fdb_external_learn_add()

If we setup the fdb flags prior to calling fdb_create() we can avoid
two atomic bitops when learning a new entry.
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/br_fdb.c

@@ -1113,14 +1113,15 @@ int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
 
 	fdb = br_fdb_find(br, addr, vid);
 	if (!fdb) {
-		fdb = fdb_create(br, p, addr, vid, 0);
+		unsigned long flags = BIT(BR_FDB_ADDED_BY_EXT_LEARN);
+
+		if (swdev_notify)
+			flags |= BIT(BR_FDB_ADDED_BY_USER);
+		fdb = fdb_create(br, p, addr, vid, flags);
 		if (!fdb) {
 			err = -ENOMEM;
 			goto err_unlock;
 		}
-		if (swdev_notify)
-			set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags);
-		set_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags);
 		fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify);
 	} else {
 		fdb->updated = jiffies;