cpuidle: make __cpuidle_device_init() return void

The only value returned by __cpuidle_device_init() is 0, so it very
well may be a void function.  Make that happen.

[rjw: Changelog]
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpuidle/cpuidle.c

@@ -358,12 +358,10 @@ static void __cpuidle_unregister_device(struct cpuidle_device *dev)
 	module_put(drv->owner);
 }
 
-static int __cpuidle_device_init(struct cpuidle_device *dev)
+static void __cpuidle_device_init(struct cpuidle_device *dev)
 {
 	memset(dev->states_usage, 0, sizeof(dev->states_usage));
 	dev->last_residency = 0;
-
-	return 0;
 }
 
 /**
@@ -410,9 +408,7 @@ int cpuidle_register_device(struct cpuidle_device *dev)
 	if (dev->registered)
 		goto out_unlock;
 
-	ret = __cpuidle_device_init(dev);
-	if (ret)
-		goto out_unlock;
+	__cpuidle_device_init(dev);
 
 	ret = __cpuidle_register_device(dev);
 	if (ret)