cpufreq / intel_pstate: use vzalloc() instead of vmalloc()/memset(0)

Use vzalloc() instead of vmalloc() and memset(0).
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NDirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/intel_pstate.c

@@ -709,10 +709,9 @@ static int __init intel_pstate_init(void)
 
 	pr_info("Intel P-state driver initializing.\n");
 
-	all_cpu_data = vmalloc(sizeof(void *) * num_possible_cpus());
+	all_cpu_data = vzalloc(sizeof(void *) * num_possible_cpus());
 	if (!all_cpu_data)
 		return -ENOMEM;
-	memset(all_cpu_data, 0, sizeof(void *) * num_possible_cpus());
 
 	rc = cpufreq_register_driver(&intel_pstate_driver);
 	if (rc)