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: Linus 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: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/rb532/gpio.c b/arch/mips/rb532/gpio.c
index 650d5d3..fd11085 100644
--- a/arch/mips/rb532/gpio.c
+++ b/arch/mips/rb532/gpio.c
@@ -89,7 +89,7 @@
 	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);