HID: wiimote: use unique battery names

Battery device names must be unique, otherwise registration fails if
multiple Wii Remotes are connected.

This breaks the sysfs API, but there is no known application that uses the
Wii Remote battery that I know of so we should go ahead and apply this.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-wiimote-core.c

@@ -1160,6 +1160,7 @@ static void wiimote_destroy(struct wiimote_data *wdata)
 	wiimote_leds_destroy(wdata);
 
 	power_supply_unregister(&wdata->battery);
+	kfree(wdata->battery.name);
 	input_unregister_device(wdata->accel);
 	input_unregister_device(wdata->ir);
 	input_unregister_device(wdata->input);
@@ -1216,9 +1217,14 @@ static int wiimote_hid_probe(struct hid_device *hdev,
 	wdata->battery.properties = wiimote_battery_props;
 	wdata->battery.num_properties = ARRAY_SIZE(wiimote_battery_props);
 	wdata->battery.get_property = wiimote_battery_get_property;
-	wdata->battery.name = "wiimote_battery";
 	wdata->battery.type = POWER_SUPPLY_TYPE_BATTERY;
 	wdata->battery.use_for_apm = 0;
+	wdata->battery.name = kasprintf(GFP_KERNEL, "wiimote_battery_%s",
+					wdata->hdev->uniq);
+	if (!wdata->battery.name) {
+		ret = -ENOMEM;
+		goto err_battery_name;
+	}
 
 	ret = power_supply_register(&wdata->hdev->dev, &wdata->battery);
 	if (ret) {
@@ -1254,6 +1260,8 @@ static int wiimote_hid_probe(struct hid_device *hdev,
 	return ret;
 
 err_battery:
+	kfree(wdata->battery.name);
+err_battery_name:
 	input_unregister_device(wdata->input);
 	wdata->input = NULL;
 err_input: