mfd: max77686: Make error checking consistent

Error checking across the driver is mostly consistent besides
a few exceptions, so change these exceptions for consistency.
Signed-off-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

drivers/mfd/max77686.c

@@ -134,7 +134,7 @@ static int max77686_i2c_probe(struct i2c_client *i2c,
 
 	max77686 = devm_kzalloc(&i2c->dev,
 				sizeof(struct max77686_dev), GFP_KERNEL);
-	if (max77686 == NULL)
+	if (!max77686)
 		return -ENOMEM;
 
 	i2c_set_clientdata(i2c, max77686);
@@ -153,8 +153,8 @@ static int max77686_i2c_probe(struct i2c_client *i2c,
 		return ret;
 	}
 
-	if (regmap_read(max77686->regmap,
-			 MAX77686_REG_DEVICE_ID, &data) < 0) {
+	ret = regmap_read(max77686->regmap, MAX77686_REG_DEVICE_ID, &data);
+	if (ret < 0) {
 		dev_err(max77686->dev,
 			"device not found on this channel (this is not an error)\n");
 		return -ENODEV;
@@ -180,7 +180,7 @@ static int max77686_i2c_probe(struct i2c_client *i2c,
 				  IRQF_TRIGGER_FALLING | IRQF_ONESHOT |
 				  IRQF_SHARED, 0, &max77686_irq_chip,
 				  &max77686->irq_data);
-	if (ret != 0) {
+	if (ret) {
 		dev_err(&i2c->dev, "failed to add PMIC irq chip: %d\n", ret);
 		goto err_unregister_i2c;
 	}
@@ -188,7 +188,7 @@ static int max77686_i2c_probe(struct i2c_client *i2c,
 				  IRQF_TRIGGER_FALLING | IRQF_ONESHOT |
 				  IRQF_SHARED, 0, &max77686_rtc_irq_chip,
 				  &max77686->rtc_irq_data);
-	if (ret != 0) {
+	if (ret) {
 		dev_err(&i2c->dev, "failed to add RTC irq chip: %d\n", ret);
 		goto err_del_irqc;
 	}