Fix LocaleIterator for platforms where c_char is u8

[abnormalmaps]

The main example for this would be aarch64 Android, where the current HEAD fails to build.

[geniot]

Interesting... I just had the same problem, spend a couple of hours, found the problem, fixed it and was about to create a PR when I saw this :)
Anyway my fix is about removing the usage of try_get_string altogether:

    let region = if sdl_locale.country.is_null() {
        None
    } else {
        Some(
            std::ffi::CStr::from_ptr(sdl_locale.country)
                .to_string_lossy()
                .into_owned(),
        )
    };

Btw, my target aarch64 device is TrimUI Smart Pro. What is yours?