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/usb/gadget/u_ether.c b/drivers/usb/gadget/u_ether.c
index 016f63b..aac69b5 100644
--- a/drivers/usb/gadget/u_ether.c
+++ b/drivers/usb/gadget/u_ether.c
@@ -487,7 +487,7 @@
 
 	if (!in) {
 		dev_kfree_skb_any(skb);
-		return 0;
+		return NETDEV_TX_OK;
 	}
 
 	/* apply outgoing CDC or RNDIS filters */
@@ -506,7 +506,7 @@
 				type = USB_CDC_PACKET_TYPE_ALL_MULTICAST;
 			if (!(cdc_filter & type)) {
 				dev_kfree_skb_any(skb);
-				return 0;
+				return NETDEV_TX_OK;
 			}
 		}
 		/* ignores USB_CDC_PACKET_TYPE_DIRECTED */
@@ -586,7 +586,7 @@
 		list_add(&req->list, &dev->tx_reqs);
 		spin_unlock_irqrestore(&dev->req_lock, flags);
 	}
-	return 0;
+	return NETDEV_TX_OK;
 }
 
 /*-------------------------------------------------------------------------*/