[openssl/openssl] 76ad9a: Coverity 1507484: dereference before null check

[Pauli]

  Branch: refs/heads/master
  Home:   https://github.com/openssl/openssl
  Commit: 76ad9ae6fa459af0bd804c01d3d681ec02cddb4b
      https://github.com/openssl/openssl/commit/76ad9ae6fa459af0bd804c01d3d681ec02cddb4b
  Author: Pauli <pauli at openssl.org>
  Date:   2022-08-01 (Mon, 01 Aug 2022)

  Changed paths:
    M ssl/tls_srp.c

  Log Message:
  -----------
  Coverity 1507484: dereference before null check

Reviewed-by: Hugo Landau <hlandau at openssl.org>
Reviewed-by: Tomas Mraz <tomas at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18907)