ASoC: soc-pcm: indicate error message at dpcm_path_get()

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(...);
		...
	}

Now, many place uses dpcm_path_get() like below

	ret = dpcm_path_get(...);
	if (ret < 0)
		goto error;
(A)	else if (ret == 0)
		dev_dbg(...)

But here, (A) part can be indicated at dpcm_path_get() not caller.
It is simple and readable code.

This patch do it.
Small detail behaviors will be exchanged by this patch.

	1) indicates debug info (= path numbers) if path > 0 case only
	   (It was *always* indicated).
	2) soc_dpcm_fe_runtime_update() is indicating error message
	   for paths < 0 case, but it is already done at dpcm_path_get().
	   Thus just remove it. but dev_dbg() vs dev_warn() is exchanged.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87mtv5utbj.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>