MIPS: TXx9: 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/11923/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/gpio_txx9.c

@@ -21,7 +21,7 @@ static struct txx9_pio_reg __iomem *txx9_pioptr;
 
 static int txx9_gpio_get(struct gpio_chip *chip, unsigned int offset)
 {
-	return __raw_readl(&txx9_pioptr->din) & (1 << offset);
+	return !!(__raw_readl(&txx9_pioptr->din) & (1 << offset));
 }
 
 static void txx9_gpio_set_raw(unsigned int offset, int value)