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/tulip/xircom_cb.c b/drivers/net/tulip/xircom_cb.c
index c2ca9f4..22b6a23 100644
--- a/drivers/net/tulip/xircom_cb.c
+++ b/drivers/net/tulip/xircom_cb.c
@@ -434,7 +434,7 @@
 			card->transmit_used = nextdescriptor;
 			leave("xircom-start_xmit - sent");
 			spin_unlock_irqrestore(&card->lock,flags);
-			return 0;
+			return NETDEV_TX_OK;
 	}