gpio: bt8xx: use new line value setter callbacks

struct gpio_chip now has callbacks for setting line values that return
an integer, allowing to indicate failures. Convert the driver to using
them.

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Bartosz Golaszewski <[e-mail]>

drivers/gpio/gpio-bt8xx.c

···
 	return 0;
 }
 
-static void bt8xxgpio_gpio_set(struct gpio_chip *gpio,
-			    unsigned nr, int val)
+static int bt8xxgpio_gpio_set(struct gpio_chip *gpio, unsigned int nr, int val)
 {
 	struct bt8xxgpio *bg = gpiochip_get_data(gpio);
 	u32 data;
···
 	else
 		data &= ~(1 << nr);
 	bgwrite(data, BT848_GPIO_DATA);
+
+	return 0;
 }
 
 static void bt8xxgpio_gpio_setup(struct bt8xxgpio *bg)
···
 	c->direction_input = bt8xxgpio_gpio_direction_input;
 	c->get = bt8xxgpio_gpio_get;
 	c->direction_output = bt8xxgpio_gpio_direction_output;
-	c->set = bt8xxgpio_gpio_set;
+	c->set_rv = bt8xxgpio_gpio_set;
 	c->dbg_show = NULL;
 	c->base = modparam_gpiobase;
 	c->ngpio = BT8XXGPIO_NR_GPIOS;