[openssl/openssl] a6a2dd: apps/s_server.c: Add check for OPENSSL_strdup

[pauli]

  Branch: refs/heads/master
  Home:   https://github.openssl.org/openssl/openssl
  Commit: a6a2dd9f60b3f3e93de1337ee84f9e8f33bc86a8
      https://github.openssl.org/openssl/openssl/commit/a6a2dd9f60b3f3e93de1337ee84f9e8f33bc86a8
  Author: Jiasheng Jiang <jiasheng at iscas.ac.cn>
  Date:   2022-06-22 (Wed, 22 Jun 2022)

  Changed paths:
    M apps/s_server.c

  Log Message:
  -----------
  apps/s_server.c: Add check for OPENSSL_strdup

As the potential failure of the OPENSSL_strdup(),
it should be better to check the return value and
return error if fails.

Signed-off-by: Jiasheng Jiang <jiasheng at iscas.ac.cn>

Reviewed-by: Todd Short <todd.short at me.com>
Reviewed-by: Paul Dale <pauli at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18595)