Fix blocking during draining in dmix
Fix blocking during draining in dmix

Fix the blocking during draining in dmix plugin due to ioctl
conflicts (bug #1074).  This is a temporary workaround.

mengdonglin/alsa-lib,lgirdwood/alsa-lib,zedongchen/alsa-lib,tiwai/alsa-lib,mikelima/alsa-lib,mikelima/alsa-lib,mikelima/alsa-lib,zedongchen/alsa-lib,gittup/alsa-lib,Distrotech/alsa-lib,lgirdwood/alsa-lib,tiwai/alsa-lib,tiwai/alsa-lib,mikelima/alsa-lib,Distrotech/alsa-lib,takaswie/alsa-lib,lgirdwood/alsa-lib,alsa-project/alsa-lib,tiwai/alsa-lib,takaswie/alsa-lib,takaswie/alsa-lib,Distrotech/alsa-lib,alsa-project/alsa-lib,Distrotech/alsa-lib,mengdonglin/alsa-lib,takaswie/alsa-lib,alsa-project/alsa-lib,gittup/alsa-lib,mengdonglin/alsa-lib,mengdonglin/alsa-lib,alsa-project/alsa-lib,gittup/alsa-lib,zedongchen/alsa-lib,takaswie/alsa-lib,lgirdwood/alsa-lib,gittup/alsa-lib,zedongchen/alsa-lib,lgirdwood/alsa-lib,zedongchen/alsa-lib,mikelima/alsa-lib,Distrotech/alsa-lib,mengdonglin/alsa-lib