leds: is31fl319x: simplify getting the adapter of a client

We have a dedicated pointer for that, so use it. Much easier to read and
less computation involved.

Signed-off-by: Wolfram Sang <[e-mail]>
Signed-off-by: Jacek Anaszewski <[e-mail]>

drivers/leds/leds-is31fl319x.c

···
 {
 	struct is31fl319x_chip *is31;
 	struct device *dev = &client->dev;
-	struct i2c_adapter *adapter = to_i2c_adapter(dev->parent);
 	int err;
 	int i = 0;
 	u32 aggregated_led_microamp = IS31FL319X_CURRENT_MAX;
 
-	if (!i2c_check_functionality(adapter, I2C_FUNC_I2C))
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
 		return -EIO;
 
 	is31 = devm_kzalloc(&client->dev, sizeof(*is31), GFP_KERNEL);