ALSA: hda - Avoid unnecessary verbs to clear PCM formats

Since really_cleanup_stream() is called from both purity_inactive_streams()
and hda_cleanup_all_streams(), the verbs to clear the PCM channel and
format may be called multiple times unnecessarily.

This patch adds checks to skip these unneeded verbs.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 6b611d5..e3db196 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -1491,8 +1491,11 @@
 				  struct hda_cvt_setup *q)
 {
 	hda_nid_t nid = q->nid;
-	snd_hda_codec_write(codec, nid, 0, AC_VERB_SET_CHANNEL_STREAMID, 0);
-	snd_hda_codec_write(codec, nid, 0, AC_VERB_SET_STREAM_FORMAT, 0);
+	if (q->stream_tag || q->channel_id)
+		snd_hda_codec_write(codec, nid, 0, AC_VERB_SET_CHANNEL_STREAMID, 0);
+	if (q->format_id)
+		snd_hda_codec_write(codec, nid, 0, AC_VERB_SET_STREAM_FORMAT, 0
+);
 	memset(q, 0, sizeof(*q));
 	q->nid = nid;
 }