ASoC: add for_each_dpcm_be() macro

To be more readable code, this patch adds
new for_each_dpcm_be() macro, and replace existing code to it.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/soc/soc-compress.c b/sound/soc/soc-compress.c
index 409d082..699397a 100644
--- a/sound/soc/soc-compress.c
+++ b/sound/soc/soc-compress.c
@@ -157,7 +157,7 @@ static int soc_compr_open_fe(struct snd_compr_stream *cstream)
 	ret = dpcm_be_dai_startup(fe, stream);
 	if (ret < 0) {
 		/* clean up all links */
-		list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be)
+		for_each_dpcm_be(fe, stream, dpcm)
 			dpcm->state = SND_SOC_DPCM_LINK_STATE_FREE;
 
 		dpcm_be_disconnect(fe, stream);
@@ -321,7 +321,7 @@ static int soc_compr_free_fe(struct snd_compr_stream *cstream)
 	ret = dpcm_be_dai_shutdown(fe, stream);
 
 	/* mark FE's links ready to prune */
-	list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be)
+	for_each_dpcm_be(fe, stream, dpcm)
 		dpcm->state = SND_SOC_DPCM_LINK_STATE_FREE;
 
 	dpcm_dapm_stream_event(fe, stream, SND_SOC_DAPM_STREAM_STOP);