greybus: power_supply: fix unregister on error path

If setup fail the release for each supply needs to know the status at
unregister time. So, add the field to the structure, update it at setup
time and use it at release.
Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
Reported-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/power_supply.c

@@ -25,6 +25,7 @@ struct gb_power_supply_prop {
 
 struct gb_power_supply {
 	u8				id;
+	bool				registered;
 #ifdef DRIVER_OWNS_PSY_STRUCT
 	struct power_supply		psy;
 #define to_gb_power_supply(x) container_of(x, struct gb_power_supply, psy)
@@ -557,9 +558,11 @@ static void _gb_power_supply_release(struct gb_power_supply *gbpsy)
 
 	cancel_delayed_work_sync(&gbpsy->work);
 #ifdef DRIVER_OWNS_PSY_STRUCT
-	power_supply_unregister(&gbpsy->psy);
+	if (gbpsy->registered)
+		power_supply_unregister(&gbpsy->psy);
 #else
-	power_supply_unregister(gbpsy->psy);
+	if (gbpsy->registered)
+		power_supply_unregister(gbpsy->psy);
 #endif
 
 	_gb_power_supply_free(gbpsy);
@@ -628,6 +631,9 @@ static int gb_power_supply_config(struct gb_power_supplies *supplies, int id)
 	schedule_delayed_work(&gbpsy->work, 0);
 
 out:
+	/* if everything went fine just mark it for release code to know */
+	if (ret == 0)
+		gbpsy->registered = true;
 	return ret;
 }