crypto: mbedtls: fix X509 info debug lifetime

[Old-Ding]

Summary

• Log the generated X509 info buffer before freeing it.
• Keep the existing success and error paths otherwise unchanged.

Root cause

x509_pm_show_info() generated certificate details into buf, freed buf, and then passed that freed pointer to SSL_DEBUG("%s", buf). When debug output is enabled this can read from freed memory.

Testing

• git diff --check
• git show --stat --check --format=fuller HEAD

Not run: local compile, because this environment does not have make, cmake, gcc, clang, or cc available.

[xiaoxiang781216]

@Old-Ding please fix:

Used config files:
    1: .codespellrc
/home/runner/work/nuttx-apps/nuttx-apps/apps/crypto/openssl_mbedtls_wrapper/mbedtls/ssl_pm.c:537: re-using ==> reusing
Some checks failed. For contributing guidelines, see:
  https://github.com/apache/nuttx/blob/master/CONTRIBUTING.md
Error: Process completed with exit code 1.

[cederom]

Thank you @Old-Ding, good catch! Please add git commit message and valid email signature :-)