ASoC: rt715-sdca: Fix return value check in rt715_sdca_sdw_probe()

In case of error, the function devm_regmap_init_sdw_mbq() and
devm_regmap_init_sdw() returns ERR_PTR() not NULL. The NULL test
in the return value check should be replaced with IS_ERR().

Fixes: 393c52d2d109 ("ASoC: rt715-sdca: Add RT715 sdca vendor-specific driver")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Link: https://lore.kernel.org/r/20210309131458.1884899-1-weiyongjun1@huawei.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/rt715-sdca-sdw.c

@@ -184,12 +184,12 @@ static int rt715_sdca_sdw_probe(struct sdw_slave *slave,
 
 	/* Regmap Initialization */
 	mbq_regmap = devm_regmap_init_sdw_mbq(slave, &rt715_sdca_mbq_regmap);
-	if (!mbq_regmap)
-		return -EINVAL;
+	if (IS_ERR(mbq_regmap))
+		return PTR_ERR(mbq_regmap);
 
 	regmap = devm_regmap_init_sdw(slave, &rt715_sdca_regmap);
-	if (!regmap)
-		return -EINVAL;
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
 
 	return rt715_sdca_init(&slave->dev, mbq_regmap, regmap, slave);
 }