MIPS: RB532: Be sure to clamp return value

As we want gpio_chip .get() calls to be able to return negative
error codes and propagate to drivers, we need to go over all
drivers and make sure their return values are clamped to [0,1].
We do this by using the ret = !!(val) design pattern.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Cc: linux-mips@linux-mips.org
Cc: linux-gpio@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11924/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

arch/mips/rb532/gpio.c

@@ -89,7 +89,7 @@ static int rb532_gpio_get(struct gpio_chip *chip, unsigned offset)
 	struct rb532_gpio_chip	*gpch;
 
 	gpch = container_of(chip, struct rb532_gpio_chip, chip);
-	return rb532_get_bit(offset, gpch->regbase + GPIOD);
+	return !!rb532_get_bit(offset, gpch->regbase + GPIOD);
 }
 
 /*