MIPS: ar7: 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>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: Alban Bedel <albeu@free.fr>
Cc: linux-mips@linux-mips.org
Cc: linux-gpio@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11922/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/ar7/gpio.c

@@ -37,7 +37,7 @@ static int ar7_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
 				container_of(chip, struct ar7_gpio_chip, chip);
 	void __iomem *gpio_in = gpch->regs + AR7_GPIO_INPUT;
 
-	return readl(gpio_in) & (1 << gpio);
+	return !!(readl(gpio_in) & (1 << gpio));
 }
 
 static int titan_gpio_get_value(struct gpio_chip *chip, unsigned gpio)