ALSA: pcm: use helper functions to refer parameters as constants

To fixup some parameters, ALSA PCM core refers the other parameters as
constants. There're some macros for this purpose.

This commit replaces codes with them.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/core/pcm_native.c

@@ -444,8 +444,8 @@ int snd_pcm_hw_refine(struct snd_pcm_substream *substream,
 		      struct snd_pcm_hw_params *params)
 {
 	struct snd_pcm_hardware *hw;
-	struct snd_interval *i = NULL;
-	struct snd_mask *m = NULL;
+	const struct snd_interval *i;
+	const struct snd_mask *m;
 	int err;
 
 	params->info = 0;
@@ -470,13 +470,13 @@ int snd_pcm_hw_refine(struct snd_pcm_substream *substream,
 		return err;
 
 	if (!params->msbits) {
-		i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
+		i = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
 		if (snd_interval_single(i))
 			params->msbits = snd_interval_value(i);
 	}
 
 	if (!params->rate_den) {
-		i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
+		i = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_RATE);
 		if (snd_interval_single(i)) {
 			params->rate_num = snd_interval_value(i);
 			params->rate_den = 1;
@@ -492,8 +492,8 @@ int snd_pcm_hw_refine(struct snd_pcm_substream *substream,
 					  SNDRV_PCM_INFO_MMAP_VALID);
 	}
 	if (!params->fifo_size) {
-		m = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
-		i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
+		m = hw_param_mask_c(params, SNDRV_PCM_HW_PARAM_FORMAT);
+		i = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_CHANNELS);
 		if (snd_mask_single(m) && snd_interval_single(i)) {
 			err = substream->ops->ioctl(substream,
 					SNDRV_PCM_IOCTL1_FIFO_SIZE, params);