ALSA: hda - Downgrade error message for single-cmd fallback

We made the error message for the CORB/RIRB communication clearer by
upgrading to dev_WARN() so that user can notice better.  But this
struck us like a boomerang: now it caught syzbot and reported back as
a fatal issue although it's not really any too serious bug that worth
for stopping the whole system.

OK, OK, let's be softy, downgrade it to the standard dev_err() again.

Fixes: dd65f7e1 ("ALSA: hda - Show the fatal CORB/RIRB error more clearly")
Reported-by: syzbot+b3028ac3933f5c466389@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/20191216151224.30013-1-tiwai@suse.deSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/hda/hda_controller.c

@@ -883,7 +883,7 @@ static int azx_rirb_get_response(struct hdac_bus *bus, unsigned int addr,
 		return -EAGAIN; /* give a chance to retry */
 	}
 
-	dev_WARN(chip->card->dev,
+	dev_err(chip->card->dev,
 		"azx_get_response timeout, switching to single_cmd mode: last cmd=0x%08x\n",
 		bus->last_cmd[addr]);
 	chip->single_cmd = 1;