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/mipsnet.c b/drivers/net/mipsnet.c
index b3b9a14..8ea98bd 100644
--- a/drivers/net/mipsnet.c
+++ b/drivers/net/mipsnet.c
@@ -141,7 +141,7 @@
 	netif_stop_queue(dev);
 	mipsnet_put_todevice(dev, skb);
 
-	return 0;
+	return NETDEV_TX_OK;
 }
 
 static inline ssize_t mipsnet_get_fromdev(struct net_device *dev, size_t len)