[openssl/openssl] c6b5c0: Fix bn_gcd code to check return value when calling...

[slontis]

  Branch: refs/heads/openssl-3.0
  Home:   https://github.openssl.org/openssl/openssl
  Commit: c6b5c00c0e6a95eb68b936e0a2a55741717c642a
      https://github.openssl.org/openssl/openssl/commit/c6b5c00c0e6a95eb68b936e0a2a55741717c642a
  Author: slontis <shane.lontis at oracle.com>
  Date:   2022-07-05 (Tue, 05 Jul 2022)

  Changed paths:
    M crypto/bn/bn_gcd.c

  Log Message:
  -----------
  Fix bn_gcd code to check return value when calling BN_one()

BN_one() uses the expand function which calls malloc which may fail.
All other places that reference BN_one() check the return value.

The issue is triggered by a memory allocation failure.
Detected by PR #18355

Reviewed-by: Tomas Mraz <tomas at openssl.org>
Reviewed-by: Paul Dale <pauli at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18697)

(cherry picked from commit 7fe7cc57af3db1e497877f0329ba17609b2efc8b)