cpufreq: mediatek: Fix NULL pointer dereference in mediatek-cpufreq

Fix following coccicheck error:
drivers/cpufreq/mediatek-cpufreq.c:464:16-23: ERROR: info is NULL but dereferenced.

Use pr_err instead of dev_err to avoid dereferring a NULL pointer.

Fixes: f52b16ba9fe4 ("cpufreq: mediatek: Use device print to show logs")
Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

drivers/cpufreq/mediatek-cpufreq.c

@@ -461,8 +461,8 @@ static int mtk_cpufreq_init(struct cpufreq_policy *policy)
 
 	info = mtk_cpu_dvfs_info_lookup(policy->cpu);
 	if (!info) {
-		dev_err(info->cpu_dev,
-			"dvfs info for cpu%d is not initialized.\n", policy->cpu);
+		pr_err("dvfs info for cpu%d is not initialized.\n",
+			policy->cpu);
 		return -EINVAL;
 	}