[openssl/openssl] 9f9dc8: Fix a possible memory leak in custom_ext_add

[Bernd Edlinger]

  Branch: refs/heads/openssl-3.2
  Home:   https://github.com/openssl/openssl
  Commit: 9f9dc855adf7e9a65b4a0de7fa1ea19d0a55094f
      https://github.com/openssl/openssl/commit/9f9dc855adf7e9a65b4a0de7fa1ea19d0a55094f
  Author: Bernd Edlinger <bernd.edlinger at hotmail.de>
  Date:   2023-11-08 (Wed, 08 Nov 2023)

  Changed paths:
    M ssl/statem/extensions_cust.c

  Log Message:
  -----------
  Fix a possible memory leak in custom_ext_add

Reviewed-by: Hugo Landau <hlandau at openssl.org>
Reviewed-by: Matt Caswell <matt at openssl.org>
Reviewed-by: Paul Dale <pauli at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/22638)

(cherry picked from commit 668a144f0a6dcfb9f904043c29372cbf19856c39)