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>

drivers/net/smc91x.c

@@ -655,7 +655,7 @@ static int smc_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
 		dev->stats.tx_errors++;
 		dev->stats.tx_dropped++;
 		dev_kfree_skb(skb);
-		return 0;
+		return NETDEV_TX_OK;
 	}
 
 	smc_special_lock(&lp->lock);
@@ -692,7 +692,7 @@ static int smc_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
 		smc_hardware_send_pkt((unsigned long)dev);
 	}
 
-	return 0;
+	return NETDEV_TX_OK;
 }
 
 /*