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/wan/hdlc_fr.c b/drivers/net/wan/hdlc_fr.c
index bfa0161..52438c7 100644
--- a/drivers/net/wan/hdlc_fr.c
+++ b/drivers/net/wan/hdlc_fr.c
@@ -421,7 +421,7 @@
 							     GFP_ATOMIC)) {
 						dev->stats.tx_dropped++;
 						dev_kfree_skb(skb);
-						return 0;
+						return NETDEV_TX_OK;
 					}
 				skb_put(skb, pad);
 				memset(skb->data + len, 0, pad);
@@ -435,13 +435,13 @@
 				dev->stats.tx_compressed++;
 			skb->dev = pvc->frad;
 			dev_queue_xmit(skb);
-			return 0;
+			return NETDEV_TX_OK;
 		}
 	}
 
 	dev->stats.tx_dropped++;
 	dev_kfree_skb(skb);
-	return 0;
+	return NETDEV_TX_OK;
 }
 
 static inline void fr_log_dlci_active(pvc_device *pvc)