Function PEM_write_bio_ECPrivateKey 

pub unsafe extern "C" fn PEM_write_bio_ECPrivateKey(
    bio: *mut BIO,
    in_: *const EC_KEY,
    enc: *const EVP_CIPHER,
    pass: *const u8,
    pass_len: c_int,
    cb: pem_password_cb,
    userdata: *mut c_void,
) -> c_int