ASoC: samsung: s3c24xx-i2s: Fix return value check in s3c24xx_iis_dev_probe()

In case of error, the function devm_ioremap_resource() returns
ERR_PTR() and never returns NULL. The NULL test in the return
value check should be replaced with IS_ERR().
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

sound/soc/samsung/s3c24xx-i2s.c

@@ -461,8 +461,8 @@ static int s3c24xx_iis_dev_probe(struct platform_device *pdev)
 		return -ENOENT;
 	}
 	s3c24xx_i2s.regs = devm_ioremap_resource(&pdev->dev, res);
-	if (s3c24xx_i2s.regs == NULL)
-		return -ENXIO;
+	if (IS_ERR(s3c24xx_i2s.regs))
+		return PTR_ERR(s3c24xx_i2s.regs);
 
 	s3c24xx_i2s_pcm_stereo_out.dma_addr = res->start + S3C2410_IISFIFO;
 	s3c24xx_i2s_pcm_stereo_in.dma_addr = res->start + S3C2410_IISFIFO;