net: use NETDEV_TX_OK instead of 0 in ndo_start_xmit() functions

This patch is the result of an automatic spatch transformation to convert
all ndo_start_xmit() return values of 0 to NETDEV_TX_OK.

Some occurences are missed by the automatic conversion, those will be
handled in a seperate patch.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index 1097c72..f1d753d 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -189,17 +189,17 @@
 	rcv_stats->rx_packets++;
 
 	netif_rx(skb);
-	return 0;
+	return NETDEV_TX_OK;
 
 tx_drop:
 	kfree_skb(skb);
 	stats->tx_dropped++;
-	return 0;
+	return NETDEV_TX_OK;
 
 rx_drop:
 	kfree_skb(skb);
 	rcv_stats->rx_dropped++;
-	return 0;
+	return NETDEV_TX_OK;
 }
 
 /*