net: convert remaining non-symbolic return values in ndo_start_xmit() functions

This patch converts the remaining occurences of raw return values to their
symbolic counterparts in ndo_start_xmit() functions that were missed by the
previous automatic conversion.

Additionally code that assumed the symbolic value of NETDEV_TX_OK to be zero
is changed to explicitly use NETDEV_TX_OK.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/depca.c b/drivers/net/depca.c
index 97ea2d6..adb997c 100644
--- a/drivers/net/depca.c
+++ b/drivers/net/depca.c
@@ -1793,7 +1793,7 @@
 static int load_packet(struct net_device *dev, struct sk_buff *skb)
 {
 	struct depca_private *lp = netdev_priv(dev);
-	int i, entry, end, len, status = 0;
+	int i, entry, end, len, status = NETDEV_TX_OK;
 
 	entry = lp->tx_new;	/* Ring around buffer number. */
 	end = (entry + (skb->len - 1) / TX_BUFF_SZ) & lp->txRingMask;