Function sys_futex_wait

#[no_mangle]
pub unsafe extern "C" fn sys_futex_wait(
    address: *mut u32,
    expected: u32,
    timeout: *const timespec,
    flags: u32,
) -> i32

Like synch::futex_wait, but does extra sanity checks and takes a timespec.

Returns -EINVAL if

• address is null
• timeout is negative
• flags contains unknown flags