ACPI / battery: Fix acpi_battery_exit on acpi_battery_init_async errors

The acpi_lock_battery_dir() / acpi_bus_register_driver() calls in
acpi_battery_init_async() may fail.

Check that they succeeded before undoing them.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>