add_checked_modules_from_symbol shouldn't fail if there are no used modules
After 1760deea68f4a915a502c5602c82c7f9f8404a51 (part of !269), mkinitcpio exits with `1` when using the `kms` hook on hardware without any privacy screens.
This is not desired. If no matching modules are found in `${_autodetect_cache}`, then `add_checked_modules_from_symbol` should still return successfully.
issue