hwmon: (w83791d) Remove duplicate NULL check

Since i2c_unregister_device() became NULL-aware we may remove duplicate
NULL check.

Cc: Marc Hulsman <m.hulsman@tudelft.nl>
Cc: Jean Delvare <jdelvare@suse.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: linux-hwmon@vger.kernel.org
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/w83791d.c

@@ -1316,8 +1316,7 @@ static int w83791d_detect_subclients(struct i2c_client *client)
 /* Undo inits in case of errors */
 
 error_sc_1:
-	if (data->lm75[0] != NULL)
-		i2c_unregister_device(data->lm75[0]);
+	i2c_unregister_device(data->lm75[0]);
 error_sc_0:
 	return err;
 }
@@ -1434,10 +1433,8 @@ static int w83791d_probe(struct i2c_client *client,
 error4:
 	sysfs_remove_group(&client->dev.kobj, &w83791d_group);
 error3:
-	if (data->lm75[0] != NULL)
-		i2c_unregister_device(data->lm75[0]);
-	if (data->lm75[1] != NULL)
-		i2c_unregister_device(data->lm75[1]);
+	i2c_unregister_device(data->lm75[0]);
+	i2c_unregister_device(data->lm75[1]);
 	return err;
 }
 
@@ -1448,10 +1445,8 @@ static int w83791d_remove(struct i2c_client *client)
 	hwmon_device_unregister(data->hwmon_dev);
 	sysfs_remove_group(&client->dev.kobj, &w83791d_group);
 
-	if (data->lm75[0] != NULL)
-		i2c_unregister_device(data->lm75[0]);
-	if (data->lm75[1] != NULL)
-		i2c_unregister_device(data->lm75[1]);
+	i2c_unregister_device(data->lm75[0]);
+	i2c_unregister_device(data->lm75[1]);
 
 	return 0;
 }