hwmon: (gpio-fan) Fix fan_ctrl_init error path

In current implementation, the sysfs entries is not removed before return -ENODEV.

Creating the sysfs attribute should be the last thing done by the function,
after all the rest has been successful.
Otherwise there is a small window during which user-space can access the attribute
but the driver isn't ready to deal with the requests.

Fix it by moving sysfs_create_group to be the last thing done by the function.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Acked-by: NSimon Guinot <sguinot@lacie.com>
Signed-off-by: NGuenter Roeck <guenter.roeck@ericsson.com>

drivers/hwmon/gpio-fan.c

@@ -376,10 +376,6 @@ static int fan_ctrl_init(struct gpio_fan_data *fan_data,
 		}
 	}
 
-	err = sysfs_create_group(&pdev->dev.kobj, &gpio_fan_ctrl_group);
-	if (err)
-		goto err_free_gpio;
-
 	fan_data->num_ctrl = num_ctrl;
 	fan_data->ctrl = ctrl;
 	fan_data->num_speed = pdata->num_speed;
@@ -391,6 +387,10 @@ static int fan_ctrl_init(struct gpio_fan_data *fan_data,
 		goto err_free_gpio;
 	}
 
+	err = sysfs_create_group(&pdev->dev.kobj, &gpio_fan_ctrl_group);
+	if (err)
+		goto err_free_gpio;
+
 	return 0;
 
 err_free_gpio: