cpufreq: mediatek: fix passing zero to 'PTR_ERR'

In order to prevent passing zero to 'PTR_ERR' in
mtk_cpu_dvfs_info_init(), we fix the return value of of_get_cci() using
error pointer by explicitly casting error number.
Signed-off-by: Jia-Wei Chang <jia-wei.chang@mediatek.com>
Fixes: 0daa4732 ("cpufreq: mediatek: Link CCI device to CPU")
Reported-by: Dan Carpenter <error27@gmail.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

drivers/cpufreq/mediatek-cpufreq.c

@@ -373,13 +373,13 @@ static struct device *of_get_cci(struct device *cpu_dev)
 	struct platform_device *pdev;
 
 	np = of_parse_phandle(cpu_dev->of_node, "mediatek,cci", 0);
-	if (IS_ERR_OR_NULL(np))
-		return NULL;
+	if (!np)
+		return ERR_PTR(-ENODEV);
 
 	pdev = of_find_device_by_node(np);
 	of_node_put(np);
-	if (IS_ERR_OR_NULL(pdev))
-		return NULL;
+	if (!pdev)
+		return ERR_PTR(-ENODEV);
 
 	return &pdev->dev;
 }
@@ -401,7 +401,7 @@ static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu)
 	info->ccifreq_bound = false;
 	if (info->soc_data->ccifreq_supported) {
 		info->cci_dev = of_get_cci(info->cpu_dev);
-		if (IS_ERR_OR_NULL(info->cci_dev)) {
+		if (IS_ERR(info->cci_dev)) {
 			ret = PTR_ERR(info->cci_dev);
 			dev_err(cpu_dev, "cpu%d: failed to get cci device\n", cpu);
 			return -ENODEV;