[openssl/openssl] b85d53: Fix missing null check

[Graham Woodward]

  Branch: refs/heads/master
  Home:   https://github.com/openssl/openssl
  Commit: b85d53c1670e47273827bba508daff310c3263ab
      https://github.com/openssl/openssl/commit/b85d53c1670e47273827bba508daff310c3263ab
  Author: Graham Woodward <graham.woodward at ibm.com>
  Date:   2022-09-30 (Fri, 30 Sep 2022)

  Changed paths:
    M crypto/cmp/cmp_util.c

  Log Message:
  -----------
  Fix missing null check

Don't add 1 if strchr returns NULL

PR update

Fixes #19279

Reviewed-by: David von Oheimb <david.von.oheimb at siemens.com>
Reviewed-by: Hugo Landau <hlandau at openssl.org>
Reviewed-by: Tomas Mraz <tomas at openssl.org>
Reviewed-by: Matt Caswell <matt at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/19282)