ALSA: oxfw: fix return value in error path of isochronous resources reservation

Even if isochronous resources reservation fails, error code doesn't return
in pcm.hw_params callback.

Cc: <stable@vger.kernel.org> #5.3+
Fixes: 4f380d00 ("ALSA: oxfw: configure packet format in pcm.hw_params callback")
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20191209151655.GA8090@workstationSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/oxfw/oxfw-pcm.c

@@ -285,7 +285,7 @@ static int pcm_playback_hw_params(struct snd_pcm_substream *substream,
 		mutex_unlock(&oxfw->mutex);
 	}
 
-	return 0;
+	return err;
 }
 
 static int pcm_capture_hw_free(struct snd_pcm_substream *substream)