dmix plugin: drain - quickfix for the previous patch
dmix plugin: drain - quickfix for the previous patch

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