The pm_qos_request isn't freed properly when OSS PCM emulation is used
because it skips snd_pcm_hw_free() call but directly releases the
stream.  This resulted in Oops later.
Tested-by: Simon Kirby <sim@hostway.ca>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
                substream->ops->close(substream);
                substream->hw_opened = 0;
        }
+       if (pm_qos_request_active(&substream->latency_pm_qos_req))
+               pm_qos_remove_request(&substream->latency_pm_qos_req);
        if (substream->pcm_release) {
                substream->pcm_release(substream);
                substream->pcm_release = NULL;