net: fix network drivers ndo_start_xmit() return values (part 4)

Fix up WAN drivers that return an errno value to qdisc_restart(), causing
qdisc_restart() to print a warning an requeue/retransmit the skb.

- cycx_x25: intention appears to be to requeue the skb

Does not compile cleanly for me even without this patch, so untested.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/wan/cycx_x25.c

@@ -615,7 +615,7 @@ static int cycx_netdevice_hard_start_xmit(struct sk_buff *skb,
 		case WAN_DISCONNECTED:
 			if (cycx_x25_chan_connect(dev)) {
 				netif_stop_queue(dev);
-				return -EBUSY;
+				return NETDEV_TX_BUSY;
 			}
 			/* fall thru */
 		case WAN_CONNECTED:
@@ -624,7 +624,7 @@ static int cycx_netdevice_hard_start_xmit(struct sk_buff *skb,
 			netif_stop_queue(dev);
 
 			if (cycx_x25_chan_send(dev, skb))
-				return -EBUSY;
+				return NETDEV_TX_BUSY;
 
 			break;
 		default:
@@ -656,7 +656,7 @@ static int cycx_netdevice_hard_start_xmit(struct sk_buff *skb,
 		if (cycx_x25_chan_send(dev, skb)) {
 			/* prepare for future retransmissions */
 			skb_push(skb, 1);
-			return -EBUSY;
+			return NETDEV_TX_BUSY;
 		}
 	}