ALSA: usb-audio: Correct the return code from snd_usb_endpoint_set_params()

snd_usb_endpoint_set_params() should return zero for a success, but
currently it returns the sample rate.  Correct it.

Fixes: 2be79d5 ("ALSA: usb-audio: Split endpoint setups for hw_params and prepare (take#2)")
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Takashi Iwai <[email protected]>

Author: tiwai

sound/usb/endpoint.c

@@ -1386,6 +1386,8 @@ int snd_usb_endpoint_set_params(struct snd_usb_audio *chip,
 	ep->curframesize = ep->curpacksize / ep->cur_frame_bytes;
 
 	err = update_clock_ref_rate(chip, ep);
+	if (err >= 0)
+		err = 0;
  unlock:
 	mutex_unlock(&chip->mutex);
 	return err;