net: stmmac: qcom-ethqos: fix qcom_ethqos_serdes_powerup()

Add cleanup for failure paths in qcom_ethqos_serdes_powerup(). This
was missing calling phy_exit() and phy_power_off() at appropriate
failure points.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Tested-by: Mohd Ayaan Anwar <mohd.anwar@oss.qualcomm.com>
Reviewed-by: Mohd Ayaan Anwar <mohd.anwar@oss.qualcomm.com>
Link: https://patch.msgid.link/E1voPUH-000000083ji-25FH@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: Russell King (Oracle)

drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c

@@ -659,10 +659,18 @@ static int qcom_ethqos_serdes_powerup(struct net_device *ndev, void *priv)
 		return ret;
 
 	ret = phy_power_on(ethqos->serdes_phy);
-	if (ret)
+	if (ret) {
+		phy_exit(ethqos->serdes_phy);
 		return ret;
+	}
 
-	return phy_set_speed(ethqos->serdes_phy, ethqos->serdes_speed);
+	ret = phy_set_speed(ethqos->serdes_phy, ethqos->serdes_speed);
+	if (ret) {
+		phy_power_off(ethqos->serdes_phy);
+		phy_exit(ethqos->serdes_phy);
+	}
+
+	return ret;
 }
 
 static void qcom_ethqos_serdes_powerdown(struct net_device *ndev, void *priv)