gpiolib: sanitize the return value of gpio_chip::direction_input()

The return value of the direction_input() callback may be propagated to
user-space. As per the API contract it can only return 0 or a negative
error number. Add a wrapper around the callback calls that filters out
anything else.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20250210-gpio-sanitize-retvals-v1-7-12ea88506cb2@linaro.org


Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>