blake2s_final
rc = blake2s_final(&bctx.ss, res, ses->mlen);
void blake2s_final(struct blake2s_state *state, uint8_t *out);
blake2s_final(&state, out);
blake2s_final(&blake, key);
blake2s_final(&state, macs->mac1);
blake2s_final(&state, macs->mac2);
blake2s_final(&state, cookie);
blake2s_final(&state, cookie);
blake2s_final(&state, x_key);
blake2s_final(&state, i_hash);
blake2s_final(&state, i_hash);
blake2s_final(&blake, hash);
blake2s_final(&blake, hash);