PCM: snd_pcm_xxxx_drain() maybe blocked after suspend and resume

PCM: snd_pcm_xxxx_drain() maybe blocked after suspend and resume

After suspend and resume, the alsa driver is stopped. But if alsa-lib run
into snd_pcm_xxxx_drain(), it need to wait avail >= pcm->stop_threshold,
otherwise, it will not exit the loop, so finally it is blocked at poll() of
snd_pcm_wait_nocheck(pcm, -1).
This patch is to add state check after snd_pcm_wait_nocheck(pcm, -1), if
the state is SND_PCM_STATE_SUSPENDED, then return error.

Signed-off-by: Shengjiu Wang <shengjiu.wang@freescale.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>