gpio: janz-ttl: 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: Ira W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-janz-ttl.c

@@ -76,7 +76,7 @@ static int ttl_get_value(struct gpio_chip *gpio, unsigned offset)
 	spin_lock(&mod->lock);
 	ret = *shadow & (1 << offset);
 	spin_unlock(&mod->lock);
-	return ret;
+	return !!ret;
 }
 
 static void ttl_set_value(struct gpio_chip *gpio, unsigned offset, int value)