PM / devfreq: Fix memory leak when fail to register device

commit 9e14de10 upstream.

When the devfreq_add_device fails to register deivce, the memory
leak of devfreq instance happen. So, this patch fix the memory
leak issue. Before freeing the devfreq instance checks whether
devfreq instance is NULL or not because the device_unregister()
frees the devfreq instance when jumping to the 'err_init'.
It is to prevent the duplicate the kfee(devfreq).

Fixes: ac4b2811 ("PM / devfreq: fix duplicated kfree on devfreq pointer")
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/devfreq/devfreq.c

@@ -574,7 +574,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
 	err = device_register(&devfreq->dev);
 	if (err) {
 		mutex_unlock(&devfreq->lock);
-		goto err_out;
+		goto err_dev;
 	}
 
 	devfreq->trans_table =	devm_kzalloc(&devfreq->dev, sizeof(unsigned int) *
@@ -618,6 +618,9 @@ struct devfreq *devfreq_add_device(struct device *dev,
 	mutex_unlock(&devfreq_list_lock);
 
 	device_unregister(&devfreq->dev);
+err_dev:
+	if (devfreq)
+		kfree(devfreq);
 err_out:
 	return ERR_PTR(err);
 }