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/via-velocity.c b/drivers/net/via-velocity.c
index 3ba3595..42365e5 100644
--- a/drivers/net/via-velocity.c
+++ b/drivers/net/via-velocity.c
@@ -2098,7 +2098,7 @@
 #ifdef VELOCITY_ZERO_COPY_SUPPORT
 	if (skb_shinfo(skb)->nr_frags > 6 && __skb_linearize(skb)) {
 		kfree_skb(skb);
-		return 0;
+		return NETDEV_TX_OK;
 	}
 #endif