ASoC: amd: acp5x-mach:add checks to avoid static analysis warnings

snd_soc_card_get_codec_dai() can return NULL, but that value is not
checked for, leading to static analysis warnings.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Reviewed-by: Daniel Baluta <daniel.baluta@nxp.com>
Reviewed-by: Yaochun Hung <yc.hung@mediatek.com>
Link: https://lore.kernel.org/r/20230731213748.440285-9-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/amd/vangogh/acp5x-mach.c

@@ -170,6 +170,9 @@ static int acp5x_nau8821_hw_params(struct snd_pcm_substream *substream,
 	struct snd_soc_dai *dai = snd_soc_card_get_codec_dai(card, ACP5X_NAU8821_DAI_NAME);
 	int ret, bclk;
 
+	if (!dai)
+		return -EINVAL;
+
 	ret = snd_soc_dai_set_sysclk(dai, NAU8821_CLK_FLL_BLK, 0, SND_SOC_CLOCK_IN);
 	if (ret < 0)
 		dev_err(card->dev, "can't set FS clock %d\n", ret);