batman-adv: Update wifi flags on upper link change

Things like VLANs don't have their link set when they are created. Thus
the wifi flags have to be evaluated later to fix their contents for the
link interface.

Signed-off-by: Sven Eckelmann <sven.eckelmann@open-mesh.com>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

net/batman-adv/hard-interface.c

@@ -1006,6 +1006,11 @@ static int batadv_hard_if_event(struct notifier_block *this,
 		if (hard_iface == primary_if)
 			batadv_primary_if_update_addr(bat_priv, NULL);
 		break;
+	case NETDEV_CHANGEUPPER:
+		hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
+		if (batadv_is_wifi_hardif(hard_iface))
+			hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
+		break;
 	default:
 		break;
 	}