net: hns: Restart autoneg need return failed when autoneg off

[ Upstream commit ed29ca8b9592562559c64d027fb5eb126e463e2c ]

The hns driver of earlier devices, when autoneg off, restart autoneg
will return -EINVAL, so make the hns driver for the latest devices
do the same.
Signed-off-by: NYonglong Liu <liuyonglong@huawei.com>
Signed-off-by: NPeng Li <lipeng321@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NSasha Levin <sashal@kernel.org>

drivers/net/ethernet/hisilicon/hns/hns_ethtool.c

@@ -1157,16 +1157,18 @@ static int hns_get_regs_len(struct net_device *net_dev)
  */
 static int hns_nic_nway_reset(struct net_device *netdev)
 {
-	int ret = 0;
 	struct phy_device *phy = netdev->phydev;
 
-	if (netif_running(netdev)) {
-		/* if autoneg is disabled, don't restart auto-negotiation */
-		if (phy && phy->autoneg == AUTONEG_ENABLE)
-			ret = genphy_restart_aneg(phy);
-	}
+	if (!netif_running(netdev))
+		return 0;
 
-	return ret;
+	if (!phy)
+		return -EOPNOTSUPP;
+
+	if (phy->autoneg != AUTONEG_ENABLE)
+		return -EINVAL;
+
+	return genphy_restart_aneg(phy);
 }
 
 static u32