[openssl/openssl] ef2a43: X509_NAME_cmp fix for empty name

[Wim Decroix]

  Branch: refs/heads/openssl-3.0
  Home:   https://github.com/openssl/openssl
  Commit: ef2a438d9d94c323b70bf8bd0b4c6ef6542d1a9d
      https://github.com/openssl/openssl/commit/ef2a438d9d94c323b70bf8bd0b4c6ef6542d1a9d
  Author: Wim Decroix <wim.decroix at auth0.com>
  Date:   2023-06-12 (Mon, 12 Jun 2023)

  Changed paths:
    M crypto/x509/x509_cmp.c

  Log Message:
  -----------
  X509_NAME_cmp fix for empty name

CLA: trivial

Fixes #21156

Reviewed-by: Todd Short <todd.short at me.com>
Reviewed-by: Tomas Mraz <tomas at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/21155)

(cherry picked from commit ec59752835f616860cd9451d6cfcea16bfc3ad05)