ASoC: soc-pcm: indicate error message at dpcm_run_update_startup/shutdown()

Indicating error message when failed case is very useful for debuging.
In many case, its style is like below.

	int function(...)
	{
		...
		return ret;
	}

	int caller(...)
	{
		...
		ret = function(...);
		if (ret < 0)
			dev_err(...)
		...
	}

This is not so bad, but in this style *each caller* needs to indicate
duplicate same error message, and some caller is forgetting to do it.
And caller can't indicate detail function() error information.

If function() indicates error message, we can get same and
detail information without forgot.

	int function(...)
	{
		...
		if (ret < 0)
			dev_err(...)

		return ret;
	}

	int caller(...)
	{
		...
		ret = function(...);
		...
	}

This patch also
do below to dpcm_run_update_startup()
	1) remove duplicated ret = -EINVAL
	2) remove blank line
do below to dpcm_run_update_shutdown()
	1) remove unused ret
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87im5tutb3.wl-kuninori.morimoto.gx@renesas.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/soc-pcm.c

@@ -2325,7 +2325,10 @@ static int dpcm_run_update_shutdown(struct snd_soc_pcm_runtime *fe, int stream)
 	/* run the stream event for each BE */
 	dpcm_dapm_stream_event(fe, stream, SND_SOC_DAPM_STREAM_NOP);
 
-	return 0;
+	if (err < 0)
+		dev_err(fe->dev, "ASoC: %s() failed (%d)\n", __func__, err);
+
+	return err;
 }
 
 static int dpcm_run_update_startup(struct snd_soc_pcm_runtime *fe, int stream)
@@ -2366,7 +2369,6 @@ static int dpcm_run_update_startup(struct snd_soc_pcm_runtime *fe, int stream)
 	if (fe->dpcm[stream].state == SND_SOC_DPCM_STATE_HW_PARAMS)
 		return 0;
 
-
 	ret = dpcm_be_dai_prepare(fe, stream);
 	if (ret < 0)
 		goto hw_free;
@@ -2421,6 +2423,9 @@ static int dpcm_run_update_startup(struct snd_soc_pcm_runtime *fe, int stream)
 	}
 	spin_unlock_irqrestore(&fe->card->dpcm_lock, flags);
 
+	if (ret < 0)
+		dev_err(fe->dev, "ASoC: %s() failed (%d)\n", __func__, ret);
+
 	return ret;
 }
 
@@ -2429,7 +2434,6 @@ static int soc_dpcm_fe_runtime_update(struct snd_soc_pcm_runtime *fe, int new)
 	struct snd_soc_dapm_widget_list *list;
 	int stream;
 	int count, paths;
-	int ret;
 
 	if (!fe->dai_link->dynamic)
 		return 0;
@@ -2469,11 +2473,9 @@ static int soc_dpcm_fe_runtime_update(struct snd_soc_pcm_runtime *fe, int new)
 		if (count) {
 			dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_BE);
 			if (new)
-				ret = dpcm_run_update_startup(fe, stream);
+				dpcm_run_update_startup(fe, stream);
 			else
-				ret = dpcm_run_update_shutdown(fe, stream);
-			if (ret < 0)
-				dev_err(fe->dev, "ASoC: failed to shutdown some BEs\n");
+				dpcm_run_update_shutdown(fe, stream);
 			dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_NO);
 
 			dpcm_clear_pending_state(fe, stream);