ucm: fix _alibpref string (add '.' delimiter to the end)
ucm: fix _alibpref string (add '.' delimiter to the end)

Fixes: 0e4ba2ea ("ucm: add _alibpref to get the private device prefix")
Signed-off-by: Jaroslav Kysela <72edd5e1a572f82f059ccbb83c92b74d6cb051ff@perex.cz>

alsa-project/alsa-lib,alsa-project/alsa-lib,tiwai/alsa-lib,tiwai/alsa-lib,alsa-project/alsa-lib,alsa-project/alsa-lib,tiwai/alsa-lib,tiwai/alsa-lib