Since alsa-utils 1.2.5 alsactl will print messages to standard error
if the HDA model does not support UCM. Apparently, this is intended by
upstream and users should manually disable UCM if they don't want to see
these messages.
See https://github.com/alsa-project/alsa-lib/issues/159#issuecomment-862441961
Use the latest and greatest OpenRC ALSA service from the Gentoo portage
tree. This new service no longer supports any modular auto(un)loading of
ALSA core modules, which shouldn't be a problem since the load_modules()
function didn't even work before.
