ALSA: pcm: Set missing stop_operating flag at undoing trigger start

When a PCM trigger-start fails at snd_pcm_do_start(), PCM core tries
to undo the action at snd_pcm_undo_start() by issuing the trigger STOP
manually.  At that point, we forgot to set the stop_operating flag,
hence the sync-stop won't be issued at the next prepare or other
calls.

This patch adds the missing stop_operating flag at
snd_pcm_undo_start().

Fixes: 1e850bee ("ALSA: pcm: Add the support for sync-stop operation")
Link: https://lore.kernel.org/r/b4e71631-4a94-613-27b2-fb595792630@carlh.net
Link: https://lore.kernel.org/r/20221205132124.11585-2-tiwai@suse.deSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/core/pcm_native.c

@@ -1432,8 +1432,10 @@ static int snd_pcm_do_start(struct snd_pcm_substream *substream,
 static void snd_pcm_undo_start(struct snd_pcm_substream *substream,
 			       snd_pcm_state_t state)
 {
-	if (substream->runtime->trigger_master == substream)
+	if (substream->runtime->trigger_master == substream) {
 		substream->ops->trigger(substream, SNDRV_PCM_TRIGGER_STOP);
+		substream->runtime->stop_operating = true;
+	}
 }
 
 static void snd_pcm_post_start(struct snd_pcm_substream *substream,