snd_usb_endpoint_set_params() should return zero for a success, but
currently it returns the sample rate.  Correct it.
Fixes: 2be79d586454 ("ALSA: usb-audio: Split endpoint setups for hw_params and prepare (take#2)")
Link: https://lore.kernel.org/r/20221009104212.18877-4-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
 
        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;