ALSA: firewire-motu: fix error return code in snd_motu_stream_reserve_duplex()

Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.

Fixes: e50dfac8 ("ALSA: firewire-motu: cache event ticks in source packet header per data block")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Acked-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20210603143203.582017-1-yangyingliang@huawei.comSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/motu/motu-stream.c

@@ -191,7 +191,7 @@ int snd_motu_stream_reserve_duplex(struct snd_motu *motu, unsigned int rate,
 		if (!motu->cache.event_offsets) {
 			fw_iso_resources_free(&motu->tx_resources);
 			fw_iso_resources_free(&motu->rx_resources);
-			return err;
+			return -ENOMEM;
 		}
 	}