net/at91_ether: fix error return code in at91ether_probe()

Fix to return a negative error code from the error handling
case instead of 0, as returned elsewhere in this function.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/cadence/at91_ether.c

@@ -394,7 +394,8 @@ static int __init at91ether_probe(struct platform_device *pdev)
 	if (res)
 		goto err_disable_clock;
 
-	if (macb_mii_init(lp) != 0)
+	res = macb_mii_init(lp);
+	if (res)
 		goto err_out_unregister_netdev;
 
 	/* will be enabled in open() */