Function io_uring_prep_readv_fixed 

pub unsafe fn io_uring_prep_readv_fixed(
    sqe: *mut io_uring_sqe,
    fd: c_int,
    iovecs: *const iovec,
    nr_vecs: c_uint,
    offset: u64,
    flags: c_int,
    buf_index: c_int,
)