net: macb: use netdev_tx_t return type for ndo_start_xmit functions

Use netdev_tx_t return type for ndo_start_xmit function of macb driver.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 file changed