drivers/gpio/it8761e_gpio: check return value of gpiochip_remove()

This eliminates the following build warning:

drivers/gpio/it8761e_gpio.c: In function `it8761e_gpio_exit':
drivers/gpio/it8761e_gpio.c:220: warning: ignoring return value of `gpiochip_remove', declared with attribute warn_unused_result

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Denis Turischev <denis@compulab.co.il>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/gpio/it8761e_gpio.c

@@ -217,7 +217,10 @@ gpiochip_add_err:
 static void __exit it8761e_gpio_exit(void)
 {
 	if (gpio_ba) {
-		gpiochip_remove(&it8761e_gpio_chip);
+		int ret = gpiochip_remove(&it8761e_gpio_chip);
+
+		WARN(ret, "%s(): gpiochip_remove() failed, ret=%d\n",
+				__func__, ret);
 
 		release_region(gpio_ba, GPIO_IOSIZE);
 		gpio_ba = 0;