belt_encrypt
void belt_encrypt(const u8 in[BELT_BLOCK_LEN], u8 out[BELT_BLOCK_LEN], const u8 ks[BELT_KEY_SCHED_LEN]);
belt_encrypt(tmp1, tmp2, x);
belt_encrypt(tmp1, s, x);
belt_encrypt(x, result, teta);
belt_encrypt(&x[BELT_BLOCK_LEN], &result[BELT_BLOCK_LEN], teta);
belt_encrypt(s, &r[(n - 2) * BELT_BLOCK_LEN], theta);