[U-Boot] unsigned int for gpio

[Jeroen Hofstee <jeroen@myspectrum.nl>]

Hello Simon,

in commit 95a260a9


dm: Enable gpio command to support driver model
    
Now that named GPIO banks are supported, along with a way of obtaining
the status of a GPIO (input or output), we can provide an enhanced
GPIO command for driver model. Where the driver provides its own
operation for obtaining the GPIO state, this is used, otherwise a
generic version is sufficient.

you made the following change:

-       int gpio;
+       unsigned int gpio;

This breaks the code after it though:

        /* turn the gpio name into a gpio number */
        gpio = name_to_gpio(str_gpio);
        if (gpio < 0)
                goto show_usage;

And causes warnings with clang like:

common/cmd_gpio.c:159:11: warning: comparison of unsigned expression < 0
is always false [-Wtautological-compare]
        if (gpio < 0)
            ~~~~ ^ ~

Do you recall why it is made unsigned?

Regards,
Jeroen