cpuidle: call cpuidle_get_driver() from after taking cpuidle_driver_lock

There are a few cpuidle_get_driver() calls that aren't made under
cpuidle_driver_lock which is incorrect.

Fix them by calling cpuidle_get_driver() after taking cpuidle_driver_lock.
Acked-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpuidle/driver.c

@@ -338,10 +338,11 @@ struct cpuidle_driver *cpuidle_driver_ref(void)
  */
 void cpuidle_driver_unref(void)
 {
-	struct cpuidle_driver *drv = cpuidle_get_driver();
+	struct cpuidle_driver *drv;
 
 	spin_lock(&cpuidle_driver_lock);
 
+	drv = cpuidle_get_driver();
 	if (drv && !WARN_ON(drv->refcnt <= 0))
 		drv->refcnt--;
 

drivers/cpuidle/sysfs.c

@@ -52,9 +52,10 @@ static ssize_t show_current_driver(struct device *dev,
 				   char *buf)
 {
 	ssize_t ret;
-	struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver();
+	struct cpuidle_driver *cpuidle_driver;
 
 	spin_lock(&cpuidle_driver_lock);
+	cpuidle_driver = cpuidle_get_driver();
 	if (cpuidle_driver)
 		ret = sprintf(buf, "%s\n", cpuidle_driver->name);
 	else