[BUG] pipeline_comp_trigger() has a logic error #4746

Describe the bug
pipeline_comp_trigger() effectively does this:

	err = comp_trigger(current, ppl_data->cmd);
	if (err < 0 || err == PPL_STATUS_PATH_STOP)
		return err;

	return pipeline_for_each_comp(current, ctx, dir);

and it is called from pipeline_trigger_run() as this:

	struct pipeline_walk_context walk_ctx = {
		.comp_func = pipeline_comp_trigger,
		.comp_data = &data,
		.skip_incomplete = true,
	};

	ret = walk_ctx.comp_func(host, NULL, &walk_ctx, host->direction);

	return ret;

Also note, that pipeline_for_each_comp() ignores non-negative return codes from the iterator function:

	int err = ctx->comp_func(buffer_comp, buffer,
				 ctx, dir);
	return 0;

This means, that if pipeline_comp_trigger() returns PPL_STATUS_PATH_STOP for the first component in the pipeline, i.e. when directly called from pipeline_trigger_run(), that return code will be propagated back to the caller. However, if that code is returned by one of later pipeline components, it will be ignored. This is probably not the intended behaviour. Note, that this code has been significantly altered by my recent commits, e.g. e8d2226 but this behaviour has been preserved and can be verified in the code base before that commit.