ASoC: mmp-sspa: Fix return value check in asoc_mmp_sspa_probe()

In case of error, the function devm_ioremap() returns NULL pointer not
ERR_PTR(). The IS_ERR() test in the return value check should be
replaced with NULL test.
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Link: https://lore.kernel.org/r/20200527030210.124393-1-weiyongjun1@huawei.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/pxa/mmp-sspa.c

@@ -493,13 +493,13 @@ static int asoc_mmp_sspa_probe(struct platform_device *pdev)
 			return -ENODEV;
 
 		sspa->rx_base = devm_ioremap(&pdev->dev, res->start, 0x30);
-		if (IS_ERR(sspa->rx_base))
-			return PTR_ERR(sspa->rx_base);
+		if (!sspa->rx_base)
+			return -ENOMEM;
 
 		sspa->tx_base = devm_ioremap(&pdev->dev,
 					     res->start + 0x80, 0x30);
-		if (IS_ERR(sspa->tx_base))
-			return PTR_ERR(sspa->tx_base);
+		if (!sspa->tx_base)
+			return -ENOMEM;
 
 		sspa->clk = devm_clk_get(&pdev->dev, NULL);
 		if (IS_ERR(sspa->clk))