power_supply: Initialize changed_work before calling device_add

Calling device_add causes an inital uevent for that device to be generated.
The power_supply uevent function calls the drivers get_property function,
which might causes the driver to update its state, which again might
causes the driver to call power_supply_changed(). Since the power_supplys
changed_work has not been initialized at this point the behavior is
undefined and can result in an OOPS.

This patch fixes the issue by initializing the power_supplys changed_work
prior to adding the power_supplys device to the device tree.
Reported-by: Grazvydas Ignotas <notasas@gmail.com>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Tested-by: Grazvydas Ignotas <notasas@gmail.com>

drivers/power/power_supply_core.c

@@ -171,6 +171,8 @@ int power_supply_register(struct device *parent, struct power_supply *psy)
 	dev_set_drvdata(dev, psy);
 	psy->dev = dev;
 
+	INIT_WORK(&psy->changed_work, power_supply_changed_work);
+
 	rc = kobject_set_name(&dev->kobj, "%s", psy->name);
 	if (rc)
 		goto kobject_set_name_failed;
@@ -179,8 +181,6 @@ int power_supply_register(struct device *parent, struct power_supply *psy)
 	if (rc)
 		goto device_add_failed;
 
-	INIT_WORK(&psy->changed_work, power_supply_changed_work);
-
 	rc = power_supply_create_triggers(psy);
 	if (rc)
 		goto create_triggers_failed;