PM / devfreq: fix mem leak in devfreq_add_device()

'devfreq' is malloced in devfreq_add_device() and should be freed in
the error handling cases, otherwise it will cause memory leak.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

drivers/devfreq/devfreq.c

@@ -651,7 +651,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
 		mutex_unlock(&devfreq->lock);
 		err = set_freq_table(devfreq);
 		if (err < 0)
-			goto err_out;
+			goto err_dev;
 		mutex_lock(&devfreq->lock);
 	}