regulator: Fix deadlock on removal of regulators with supplies

If a regulator with a supply is being unregistered we will call
regulator_put() to release the supply with the regulator_list_mutex held
but this deadlocks as regulator_put() takes the same lock. Fix this by
releasing the supply before we take the mutex in regulator_unregister().
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

drivers/regulator/core.c

@@ -2992,14 +2992,14 @@ void regulator_unregister(struct regulator_dev *rdev)
 	if (rdev == NULL)
 		return;
 
+	if (rdev->supply)
+		regulator_put(rdev->supply);
 	mutex_lock(&regulator_list_mutex);
 	debugfs_remove_recursive(rdev->debugfs);
 	flush_work_sync(&rdev->disable_work.work);
 	WARN_ON(rdev->open_count);
 	unset_regulator_supplies(rdev);
 	list_del(&rdev->list);
-	if (rdev->supply)
-		regulator_put(rdev->supply);
 	kfree(rdev->constraints);
 	device_unregister(&rdev->dev);
 	mutex_unlock(&regulator_list_mutex);