net: broadcom: Fix return type for implementation of

Since Linux now supports CFI, it will be a good idea to fix mismatched
return type for implementation of hooks. Otherwise this might get
cought out by CFI and cause a panic.

bcm4908_enet_start_xmit() would return either NETDEV_TX_BUSY or
NETDEV_TX_OK, so change the return type to netdev_tx_t directly.

Signed-off-by: GUO Zihua <guozihua@huawei.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20220902075407.52358-1-guozihua@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/broadcom/bcm4908_enet.c

@@ -507,7 +507,7 @@ static int bcm4908_enet_stop(struct net_device *netdev)
 	return 0;
 }
 
-static int bcm4908_enet_start_xmit(struct sk_buff *skb, struct net_device *netdev)
+static netdev_tx_t bcm4908_enet_start_xmit(struct sk_buff *skb, struct net_device *netdev)
 {
 	struct bcm4908_enet *enet = netdev_priv(netdev);
 	struct bcm4908_enet_dma_ring *ring = &enet->tx_ring;