ASoC: mediatek: mt8195: fix return value

cppcheck reports the following warning:

sound/soc/mediatek/mt8195/mt8195-dai-etdm.c:1299:10: style: Variable
'ret' is assigned a value that is never used. [unreadVariable]
 int ret = 0;
         ^

The suggested change aligns the implementation of
mt8195_afe_disable_etdm() with mt8195_afe_enable_etdm() - same
negative return value upon error.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20211025185933.144327-8-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/mediatek/mt8195/mt8195-dai-etdm.c

@@ -1316,7 +1316,7 @@ static int mt8195_afe_disable_etdm(struct mtk_base_afe *afe, int dai_id)
 	}
 out:
 	spin_unlock_irqrestore(&afe_priv->afe_ctrl_lock, flags);
-	return 0;
+	return ret;
 }
 
 static int etdm_cowork_slv_sel(int id, int slave_mode)