pinctrl: samsung: Make samsung_pinctrl_get_soc_data use ERR_PTR()

Currently the function returns a valid pointer on success and NULL on
error, so exact error code is lost. This patch changes return convention
of the function to use ERR_PTR() on error instead.
Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>

drivers/pinctrl/samsung/pinctrl-samsung.c

@@ -981,7 +981,7 @@ static struct samsung_pin_ctrl *samsung_pinctrl_get_soc_data(
 	id = of_alias_get_id(node, "pinctrl");
 	if (id < 0) {
 		dev_err(&pdev->dev, "failed to get alias id\n");
-		return NULL;
+		return ERR_PTR(-ENOENT);
 	}
 	match = of_match_node(samsung_pinctrl_dt_match, node);
 	ctrl = (struct samsung_pin_ctrl *)match->data + id;
@@ -1033,9 +1033,9 @@ static int samsung_pinctrl_probe(struct platform_device *pdev)
 	}
 
 	ctrl = samsung_pinctrl_get_soc_data(drvdata, pdev);
-	if (!ctrl) {
+	if (IS_ERR(ctrl)) {
 		dev_err(&pdev->dev, "driver data not available\n");
-		return -EINVAL;
+		return PTR_ERR(ctrl);
 	}
 	drvdata->ctrl = ctrl;
 	drvdata->dev = dev;