Function lrw_start 

pub unsafe extern "C" fn lrw_start(
    cipher: c_int,
    IV: *const c_uchar,
    key: *const c_uchar,
    keylen: c_int,
    tweak: *const c_uchar,
    num_rounds: c_int,
    lrw: *mut symmetric_LRW,
) -> c_int