mfd: ucb1x00-core: 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: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/mfd/ucb1x00-core.c

@@ -133,7 +133,7 @@ static int ucb1x00_gpio_get(struct gpio_chip *chip, unsigned offset)
 	val = ucb1x00_reg_read(ucb, UCB_IO_DATA);
 	ucb1x00_disable(ucb);
 
-	return val & (1 << offset);
+	return !!(val & (1 << offset));
 }
 
 static int ucb1x00_gpio_direction_input(struct gpio_chip *chip, unsigned offset)