wm831x_backup: Fix wrong kfree call for devdata->backup.name

devdata->backup.name points to devdata->name, the memory for devdata->name
is part of struct wm831x_backup. Thus remove kfree call for
devdata->backup.name.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Anton Vorontsov <anton@enomsg.org>

drivers/power/wm831x_backup.c

@@ -207,7 +207,6 @@ static int wm831x_backup_remove(struct platform_device *pdev)
 	struct wm831x_backup *devdata = platform_get_drvdata(pdev);
 
 	power_supply_unregister(&devdata->backup);
-	kfree(devdata->backup.name);
 
 	return 0;
 }