[openssl/openssl] db8e45: fix: reject adding a duplicity into STACK_OF(X509_...

[Adam Šulc]

  Branch: refs/heads/openssl-3.1
  Home:   https://github.com/openssl/openssl
  Commit: db8e453e6461d8f79946badbd42eec0c505b47c4
      https://github.com/openssl/openssl/commit/db8e453e6461d8f79946badbd42eec0c505b47c4
  Author: Adam Šulc <sulcadam12 at gmail.com>
  Date:   2023-07-24 (Mon, 24 Jul 2023)

  Changed paths:
    M crypto/err/openssl.txt
    M crypto/x509/x509_att.c
    M crypto/x509/x509_err.c
    M include/crypto/x509err.h
    M include/openssl/x509err.h

  Log Message:
  -----------
  fix: reject adding a duplicity into STACK_OF(X509_ATTRIBUTE)

Function `X509at_add1_attr()` (crypto/x509/x509_att.c) rejects to add a duplicity into `*x` but it searches in a wrong stack.

Changed to search in `*x`.

CLA: trivial

Reviewed-by: Kurt Roeckx <kurt at roeckx.be>
Reviewed-by: Paul Dale <pauli at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/21505)

(cherry picked from commit 7551264186f176ca5801aa84d60c7b91d8fba31f)