can: xilinx: fix xcan_start_xmit()'s return type

The method ndo_start_xmit() is defined as returning an 'netdev_tx_t',
which is a typedef for an enum type, but the implementation in this
driver returns an 'int'.

Fix this by returning 'netdev_tx_t' in this driver too.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/xilinx_can.c

@@ -398,9 +398,9 @@ static int xcan_do_set_mode(struct net_device *ndev, enum can_mode mode)
  * function uses the next available free txbuff and populates their fields to
  * start the transmission.
  *
- * Return: 0 on success and failure value on error
+ * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY when the tx queue is full
  */
-static int xcan_start_xmit(struct sk_buff *skb, struct net_device *ndev)
+static netdev_tx_t xcan_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 {
 	struct xcan_priv *priv = netdev_priv(ndev);
 	struct net_device_stats *stats = &ndev->stats;