bgmac: propagate error codes in bgmac_probe()

bgmac_mii_register() and register_netdev() both return appropriate error
codes for the failures they would encounter, propagate this error code
instead of overriding the value with -ENOTSUPP which is not the correct
error code to return.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bgmac.c

@@ -1518,14 +1518,12 @@ static int bgmac_probe(struct bcma_device *core)
 	err = bgmac_mii_register(bgmac);
 	if (err) {
 		bgmac_err(bgmac, "Cannot register MDIO\n");
-		err = -ENOTSUPP;
 		goto err_dma_free;
 	}
 
 	err = register_netdev(bgmac->net_dev);
 	if (err) {
 		bgmac_err(bgmac, "Cannot register net device\n");
-		err = -ENOTSUPP;
 		goto err_mii_unregister;
 	}