regulator: Warn when unregistering an in-use regulator

We're probably going to start oopsing fairly soon after this happens.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

drivers/regulator/core.c

@@ -2253,6 +2253,7 @@ void regulator_unregister(struct regulator_dev *rdev)
 		return;
 
 	mutex_lock(&regulator_list_mutex);
+	WARN_ON(rdev->open_count);
 	unset_regulator_supplies(rdev);
 	list_del(&rdev->list);
 	if (rdev->supply)