Function libe2fs_sys::set_com_err_hook

pub unsafe extern "C" fn set_com_err_hook(
    arg1: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: c_long, arg3: *const c_char, arg4: va_list)>
) -> Option<unsafe extern "C" fn(arg1: *const c_char, arg2: c_long, arg3: *const c_char, arg4: va_list)>