drm/msm: Move call to PTR_ERR_OR_ZERO after reassignment

Here, a location is reset to NULL before being passed to PTR_ERR.
So, PTR_ERR should be called before its argument is reassigned
to NULL. Further to simplify things use PTR_ERR_OR_ZERO instead
of PTR_ERR and IS_ERR.

Problem found using Coccinelle.
Signed-off-by: Vaishali Thakkar <vaishali.thakkar@oracle.com>
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>
[fixed fmt string warning (s/%ld/%d/)]
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/edp/edp_ctrl.c

@@ -302,21 +302,24 @@ static void edp_clk_disable(struct edp_ctrl *ctrl, u32 clk_mask)
 static int edp_regulator_init(struct edp_ctrl *ctrl)
 {
 	struct device *dev = &ctrl->pdev->dev;
+	int ret;
 
 	DBG("");
 	ctrl->vdda_vreg = devm_regulator_get(dev, "vdda");
-	if (IS_ERR(ctrl->vdda_vreg)) {
-		pr_err("%s: Could not get vdda reg, ret = %ld\n", __func__,
-				PTR_ERR(ctrl->vdda_vreg));
+	ret = PTR_ERR_OR_ZERO(ctrl->vdda_vreg);
+	if (ret) {
+		pr_err("%s: Could not get vdda reg, ret = %d\n", __func__,
+				ret);
 		ctrl->vdda_vreg = NULL;
-		return PTR_ERR(ctrl->vdda_vreg);
+		return ret;
 	}
 	ctrl->lvl_vreg = devm_regulator_get(dev, "lvl-vdd");
-	if (IS_ERR(ctrl->lvl_vreg)) {
-		pr_err("Could not get lvl-vdd reg, %ld",
-				PTR_ERR(ctrl->lvl_vreg));
+	ret = PTR_ERR_OR_ZERO(ctrl->lvl_vreg);
+	if (ret) {
+		pr_err("%s: Could not get lvl-vdd reg, ret = %d\n", __func__,
+				ret);
 		ctrl->lvl_vreg = NULL;
-		return PTR_ERR(ctrl->lvl_vreg);
+		return ret;
 	}
 
 	return 0;