mfd: tc6393xb: 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.

Cc: Dmitry Baryshkov <dbaryshkov@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

drivers/mfd/tc6393xb.c

@@ -437,8 +437,8 @@ static int tc6393xb_gpio_get(struct gpio_chip *chip,
 	struct tc6393xb *tc6393xb = container_of(chip, struct tc6393xb, gpio);
 
 	/* XXX: does dsr also represent inputs? */
-	return tmio_ioread8(tc6393xb->scr + SCR_GPO_DSR(offset / 8))
-		& TC_GPIO_BIT(offset);
+	return !!(tmio_ioread8(tc6393xb->scr + SCR_GPO_DSR(offset / 8))
+		  & TC_GPIO_BIT(offset));
 }
 
 static void __tc6393xb_gpio_set(struct gpio_chip *chip,