[openssl/openssl] 682d4a: Fix memory leak in BN_rand_range()

[Sahil Siddiq]

  Branch: refs/heads/openssl-3.0
  Home:   https://github.com/openssl/openssl
  Commit: 682d4a1204bc0a4c19ad3dd23f09d1e76959f8cf
      https://github.com/openssl/openssl/commit/682d4a1204bc0a4c19ad3dd23f09d1e76959f8cf
  Author: valdaarhun <icegambit91 at gmail.com>
  Date:   2022-08-17 (Wed, 17 Aug 2022)

  Changed paths:
    M crypto/bn/bn_rand.c

  Log Message:
  -----------
  Fix memory leak in BN_rand_range()

The patch enables BN_rand_range() to exit immediately
if BIGNUM *rnd is NULL.

CLA: trivial

Fixes: #18951

Reviewed-by: Matt Caswell <matt at openssl.org>
Reviewed-by: Paul Dale <pauli at openssl.org>
Reviewed-by: Hugo Landau <hlandau at openssl.org>
Reviewed-by: Tomas Mraz <tomas at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18982)

(cherry picked from commit 70f589ae41928edda18470ba1c3df82af02a92b3)