batman-adv: use NO_FLAGS define instead of hard-coding 0

The definition NO_FLAGS was introduced to make the code more
readable and shall be used to initialize flag fields.

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c
index cf7f95e..24aee56 100644
--- a/net/batman-adv/gateway_client.c
+++ b/net/batman-adv/gateway_client.c
@@ -322,7 +322,7 @@
 
 		gw_node->deleted = 0;
 
-		if (new_gwflags == 0) {
+		if (new_gwflags == NO_FLAGS) {
 			gw_node->deleted = jiffies;
 			bat_dbg(DBG_BATMAN, bat_priv,
 				"Gateway %pM removed from gateway list\n",
@@ -335,7 +335,7 @@
 		goto unlock;
 	}
 
-	if (new_gwflags == 0)
+	if (new_gwflags == NO_FLAGS)
 		goto unlock;
 
 	gw_node_add(bat_priv, orig_node, new_gwflags);