net: make vlan ndo_vlan_rx_[add/kill]_vid return error value

Let caller know the result of adding/removing vlan id to/from vlan
filter.

In some drivers I make those functions to just return 0. But in those
where there is able to see if hw setup went correctly, return value is
set appropriately.

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c
index b2a55e3..b3b045c 100644
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -1869,15 +1869,15 @@
 	qeth_l3_free_vlan_addresses6(card, vid);
 }
 
-static void qeth_l3_vlan_rx_add_vid(struct net_device *dev, unsigned short vid)
+static int qeth_l3_vlan_rx_add_vid(struct net_device *dev, unsigned short vid)
 {
 	struct qeth_card *card = dev->ml_priv;
 
 	set_bit(vid, card->active_vlans);
-	return;
+	return 0;
 }
 
-static void qeth_l3_vlan_rx_kill_vid(struct net_device *dev, unsigned short vid)
+static int qeth_l3_vlan_rx_kill_vid(struct net_device *dev, unsigned short vid)
 {
 	struct qeth_card *card = dev->ml_priv;
 	unsigned long flags;
@@ -1885,7 +1885,7 @@
 	QETH_CARD_TEXT_(card, 4, "kid:%d", vid);
 	if (qeth_wait_for_threads(card, QETH_RECOVER_THREAD)) {
 		QETH_CARD_TEXT(card, 3, "kidREC");
-		return;
+		return 0;
 	}
 	spin_lock_irqsave(&card->vlanlock, flags);
 	/* unregister IP addresses of vlan device */
@@ -1893,6 +1893,7 @@
 	clear_bit(vid, card->active_vlans);
 	spin_unlock_irqrestore(&card->vlanlock, flags);
 	qeth_l3_set_multicast_list(card->dev);
+	return 0;
 }
 
 static inline int qeth_l3_rebuild_skb(struct qeth_card *card,