net: ag71xx: call phylink_disconnect_phy if ag71xx_hw_enable() fail in ag71xx_open()

If ag71xx_hw_enable() fails, call phylink_disconnect_phy() to clean up.
And if phylink_of_phy_connect() fails, nothing needs to be done.
Compile tested only.

Fixes: 892e0915 ("net: ag71xx: port to phylink")
Signed-off-by: Liu Jian <liujian56@huawei.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://lore.kernel.org/r/20221114095549.40342-1-liujian56@huawei.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/atheros/ag71xx.c

@@ -1427,7 +1427,7 @@ static int ag71xx_open(struct net_device *ndev)
 	if (ret) {
 		netif_err(ag, link, ndev, "phylink_of_phy_connect filed with err: %i\n",
 			  ret);
-		goto err;
+		return ret;
 	}
 
 	max_frame_len = ag71xx_max_frame_len(ndev->mtu);
@@ -1448,6 +1448,7 @@ static int ag71xx_open(struct net_device *ndev)
 
 err:
 	ag71xx_rings_cleanup(ag);
+	phylink_disconnect_phy(ag->phylink);
 	return ret;
 }