ASoC: img: 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-v1-7-6f8a8902b479@linaro.orgSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/img/img-i2s-in.c

@@ -395,7 +395,7 @@ static int img_i2s_in_dma_prepare_slave_config(struct snd_pcm_substream *st,
 	struct snd_pcm_hw_params *params, struct dma_slave_config *sc)
 {
 	unsigned int i2s_channels = params_channels(params) / 2;
-	struct snd_soc_pcm_runtime *rtd = st->private_data;
+	struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(st);
 	struct snd_dmaengine_dai_dma_data *dma_data;
 	int ret;
 

sound/soc/img/img-i2s-out.c

@@ -401,7 +401,7 @@ static int img_i2s_out_dma_prepare_slave_config(struct snd_pcm_substream *st,
 	struct snd_pcm_hw_params *params, struct dma_slave_config *sc)
 {
 	unsigned int i2s_channels = params_channels(params) / 2;
-	struct snd_soc_pcm_runtime *rtd = st->private_data;
+	struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(st);
 	struct snd_dmaengine_dai_dma_data *dma_data;
 	int ret;