wilc1000: let wilc_mac_xmit() return NETDEV_TX_OK

The method ndo_start_xmit() is defined as returning an 'netdev_tx_t',
which is a typedef for an enum type defining 'NETDEV_TX_OK' but this
driver returns '0' instead of 'NETDEV_TX_OK'.

Fix this by returning 'NETDEV_TX_OK' instead of '0'.

Signed-off-by: Luc Van Oostenryck <[e-mail]>
Signed-off-by: Kalle Valo <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/net/wireless/microchip/wilc1000/netdev.c

···
 
 	if (skb->dev != ndev) {
 		netdev_err(ndev, "Packet not destined to this device\n");
-		return 0;
+		return NETDEV_TX_OK;
 	}
 
 	tx_data = kmalloc(sizeof(*tx_data), GFP_ATOMIC);
 	if (!tx_data) {
 		dev_kfree_skb(skb);
 		netif_wake_queue(ndev);
-		return 0;
+		return NETDEV_TX_OK;
 	}
 
 	tx_data->buff = skb->data;
···
 		srcu_read_unlock(&wilc->srcu, srcu_idx);
 	}
 
-	return 0;
+	return NETDEV_TX_OK;
 }
 
 static int wilc_mac_close(struct net_device *ndev)