RAND_cleanup - erase the PRNG state
 #include <openssl/rand.h>
 #if OPENSSL_API_COMPAT < 0x10100000L
 void RAND_cleanup(void)
 #endif
Prior to OpenSSL 1.1.0, RAND_cleanup() released all resources used by the
  PRNG. As of version 1.1.0, it does nothing and should not be called, since no
  explicit initialisation or de-initialisation is necessary. See
  OPENSSL_init_crypto(3).
RAND_cleanup() returns no value.
RAND_cleanup() was deprecated in OpenSSL 1.1.0; do not use it. See
  OPENSSL_init_crypto(3)
Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the OpenSSL license (the "License"). You
    may not use this file except in compliance with the License. You can obtain
    a copy in the file LICENSE in the source distribution or at
    <https://www.openssl.org/source/license.html>.