ASoC: meson: Use snd_soc_substream_to_rtd() for accessing private_data

Do not open-code snd_soc_substream_to_rtd().
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240430-asoc-snd-substream-clean-v1-11-6f8a8902b479@linaro.orgSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/meson/aiu-fifo.c

@@ -25,7 +25,7 @@
 
 static struct snd_soc_dai *aiu_fifo_dai(struct snd_pcm_substream *ss)
 {
-	struct snd_soc_pcm_runtime *rtd = ss->private_data;
+	struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(ss);
 
 	return snd_soc_rtd_to_cpu(rtd, 0);
 }

sound/soc/meson/axg-fifo.c

@@ -46,7 +46,7 @@ static struct snd_pcm_hardware axg_fifo_hw = {
 
 static struct snd_soc_dai *axg_fifo_dai(struct snd_pcm_substream *ss)
 {
-	struct snd_soc_pcm_runtime *rtd = ss->private_data;
+	struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(ss);
 
 	return snd_soc_rtd_to_cpu(rtd, 0);
 }