mfd: pm8008: Fix return value check in pm8008_probe()

In case of error, the function devm_regmap_init_i2c() returns
ERR_PTR() and never returns NULL. The NULL test in the return
value check should be replaced with IS_ERR().

Fixes: 6b149f3 ("mfd: pm8008: Add driver for QCOM PM8008 PMIC")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Guru Das Srinagesh <gurus@codeaurora.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20221125073626.1868229-1-yangyingliang@huawei.com

Author: Yang Yingliang

drivers/mfd/qcom-pm8008.c

@@ -215,8 +215,8 @@ static int pm8008_probe(struct i2c_client *client)
 
 	dev = &client->dev;
 	regmap = devm_regmap_init_i2c(client, &qcom_mfd_regmap_cfg);
-	if (!regmap)
-		return -ENODEV;
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
 
 	i2c_set_clientdata(client, regmap);