batman-adv: remove extra negation in gw_out_of_range()

There is a typo here where an extra '!' made the check to the opposite
of what was intended.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c
index 9373a14..24403a7 100644
--- a/net/batman-adv/gateway_client.c
+++ b/net/batman-adv/gateway_client.c
@@ -695,7 +695,7 @@
 	}
 
 	neigh_old = find_router(bat_priv, orig_dst_node, NULL);
-	if (!!neigh_old)
+	if (!neigh_old)
 		goto out;
 
 	if (curr_tq_avg - neigh_old->tq_avg > GW_THRESHOLD)