ASoC: sprd: Fix return value check in sprd_mcdt_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().

Fixes: d7bff893 ("ASoC: sprd: Add Spreadtrum multi-channel data transfer support")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sprd/sprd-mcdt.c

@@ -951,8 +951,8 @@ static int sprd_mcdt_probe(struct platform_device *pdev)
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	mcdt->base = devm_ioremap_resource(&pdev->dev, res);
-	if (!mcdt->base)
-		return -ENOMEM;
+	if (IS_ERR(mcdt->base))
+		return PTR_ERR(mcdt->base);
 
 	mcdt->dev = &pdev->dev;
 	spin_lock_init(&mcdt->lock);