cpufreq: unicore32: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO

This patch fixes coccinelle error regarding usage of IS_ERR and
PTR_ERR instead of PTR_ERR_OR_ZERO.
Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/unicore2-cpufreq.c

@@ -60,9 +60,7 @@ static int __init ucv2_cpu_init(struct cpufreq_policy *policy)
 	policy->max = policy->cpuinfo.max_freq = 1000000;
 	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
 	policy->clk = clk_get(NULL, "MAIN_CLK");
-	if (IS_ERR(policy->clk))
-		return PTR_ERR(policy->clk);
-	return 0;
+	return PTR_ERR_OR_ZERO(policy->clk);
 }
 
 static struct cpufreq_driver ucv2_driver = {