bcm63xx_enet: delete a redundant assignment

In the function bcm_enetsw_probe(), 'ret' will be assigned by
bcm_enet_change_mtu(), so 'ret = 0' make no sense.

Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bcm63xx_enet.c

@@ -2649,7 +2649,6 @@ static int bcm_enetsw_probe(struct platform_device *pdev)
 	if (!res_mem || irq_rx < 0)
 		return -ENODEV;
 
-	ret = 0;
 	dev = alloc_etherdev(sizeof(*priv));
 	if (!dev)
 		return -ENOMEM;