ALSA: dummy: Use standard macros for fixing PCM format cast

Simplify the code with the new macros for PCM format type iterations.
This fixes the sparse warnings nicely:
  sound/drivers/dummy.c:906:25: warning: restricted snd_pcm_format_t degrades to integer
  sound/drivers/dummy.c:908:25: warning: incorrect type in argument 1 (different base types)
  sound/drivers/dummy.c:908:25:    expected restricted snd_pcm_format_t [usertype] format
  sound/drivers/dummy.c:908:25:    got int [assigned] i

No functional changes, just sparse warning fixes.

Link: https://lore.kernel.org/r/20200206163945.6797-5-tiwai@suse.deSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/drivers/dummy.c

@@ -901,10 +901,10 @@ static int snd_card_dummy_new_mixer(struct snd_dummy *dummy)
 static void print_formats(struct snd_dummy *dummy,
 			  struct snd_info_buffer *buffer)
 {
-	int i;
+	snd_pcm_format_t i;
 
-	for (i = 0; i <= SNDRV_PCM_FORMAT_LAST; i++) {
-		if (dummy->pcm_hw.formats & (1ULL << i))
+	pcm_for_each_format(i) {
+		if (dummy->pcm_hw.formats & pcm_format_to_bits(i))
 			snd_iprintf(buffer, " %s", snd_pcm_format_name(i));
 	}
 }