when snd_pcm_free() iterates the list of substream to
free them by invalid reference.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
|Ήν°‘3x