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/mace.c b/drivers/net/mace.c
index 1427755..7d7577b 100644
--- a/drivers/net/mace.c
+++ b/drivers/net/mace.c
@@ -581,7 +581,7 @@
 	netif_stop_queue(dev);
     spin_unlock_irqrestore(&mp->lock, flags);
 
-    return 0;
+    return NETDEV_TX_OK;
 }
 
 static void mace_set_multicast(struct net_device *dev)