[ALSA] sound/pci/hda: use create_singlethread_workqueue()

process_unsol_events() seems to assume a singlethread one (IOW, racey).
So, this patch uses create_singlethread_workqueue() instead of
create_workqueue().

Signed-off-by: OGAWA Hirofumi <[e-mail]>
Signed-off-by: Takashi Iwai <[e-mail]>

sound/pci/hda/hda_codec.c

···
 		snd_printk(KERN_ERR "hda_codec: can't allocate unsolicited queue\n");
 		return -ENOMEM;
 	}
-	unsol->workq = create_workqueue("hda_codec");
+	unsol->workq = create_singlethread_workqueue("hda_codec");
 	if (! unsol->workq) {
 		snd_printk(KERN_ERR "hda_codec: can't create workqueue\n");
 		kfree(unsol);