metal_led_off/on set wrong LED state

[tmcintos]

On HiFive1 RevB with current Freedom Studio, metal_led_on turns the LED OFF and metal_led_off turns the LED ON. GPIOs are being set to the wrong polarity; reversing GPIO states (0,1) in the driver produced the expected behavior:

void __metal_driver_led_on (struct metal_led *led)
{
    int pin;
    struct metal_gpio *gpio;

    pin = __metal_driver_sifive_gpio_led_pin(led);
    gpio =  __metal_driver_sifive_gpio_led_gpio(led);

    if (gpio != NULL) {
        metal_gpio_set_pin((struct metal_gpio *) gpio, pin, 0);
    }
}

void __metal_driver_led_off (struct metal_led *led)
{
    int pin;
    struct metal_gpio *gpio;

    pin = __metal_driver_sifive_gpio_led_pin(led);
    gpio =  __metal_driver_sifive_gpio_led_gpio(led);

    if (gpio != NULL) {
        metal_gpio_set_pin((struct metal_gpio *) gpio, pin, 1);
    }
}

[tmcintos]

Looks like a duplicate of #100