phy: core: Fix error checking in (devm_)phy_optional_get

Don't pass valid pointer to PTR_ERR, use PTR_ERR(phy) only when
IS_ERR(phy) is true.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

drivers/phy/phy-core.c

@@ -530,7 +530,7 @@ struct phy *phy_optional_get(struct device *dev, const char *string)
 {
 	struct phy *phy = phy_get(dev, string);
 
-	if (PTR_ERR(phy) == -ENODEV)
+	if (IS_ERR(phy) && (PTR_ERR(phy) == -ENODEV))
 		phy = NULL;
 
 	return phy;
@@ -584,7 +584,7 @@ struct phy *devm_phy_optional_get(struct device *dev, const char *string)
 {
 	struct phy *phy = devm_phy_get(dev, string);
 
-	if (PTR_ERR(phy) == -ENODEV)
+	if (IS_ERR(phy) && (PTR_ERR(phy) == -ENODEV))
 		phy = NULL;
 
 	return phy;