[ALSA] Add snd_pcm_group_for_each_entry() for code cleanup

Added a new macro snd_pcm_group_for_each_entry() just for code cleanup.
Old macros, snd_pcm_group_for_each() and snd_pcm_group_substream_entry(),
are removed.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

sound/pci/echoaudio/echoaudio.c

@@ -705,11 +705,9 @@ static int pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 	struct audiopipe *pipe = runtime->private_data;
 	int i, err;
 	u32 channelmask = 0;
-	struct list_head *pos;
 	struct snd_pcm_substream *s;
 
-	snd_pcm_group_for_each(pos, substream) {
-		s = snd_pcm_group_substream_entry(pos);
+	snd_pcm_group_for_each_entry(s, substream) {
 		for (i = 0; i < DSP_MAXPIPES; i++) {
 			if (s == chip->substream[i]) {
 				channelmask |= 1 << i;