ASoC: samsung: smdk_wm8994: add missing return

cppcheck warning:

sound/soc/samsung/smdk_wm8994.c:179:6: style: Variable 'ret' is
reassigned a value before the old one has been
used. [redundantAssignment]
 ret = devm_snd_soc_register_card(&pdev->dev, card);
     ^
sound/soc/samsung/smdk_wm8994.c:166:8: note: ret is assigned
   ret = -EINVAL;
       ^
sound/soc/samsung/smdk_wm8994.c:179:6: note: ret is overwritten
 ret = devm_snd_soc_register_card(&pdev->dev, card);
     ^

The initial authors bothered to set ret to -EINVAL and throw a
dev_err() message, so it looks like there is a missing return to avoid
continuing if the property is missing.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20210219230918.5058-4-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/samsung/smdk_wm8994.c

@@ -164,6 +164,7 @@ static int smdk_audio_probe(struct platform_device *pdev)
 			dev_err(&pdev->dev,
 			   "Property 'samsung,i2s-controller' missing or invalid\n");
 			ret = -EINVAL;
+			return ret;
 		}
 
 		smdk_dai[0].platforms->name = NULL;