[LTP] doc: Add missing API references to api_c_tests.rst

[linuxtestproject.agent@gmail.com]

Hi Andrea,

On Tue, 09 Jun 2026 12:31:57 +0200, Andrea Cervesato wrote:
> doc: Add missing API references to api_c_tests.rst

Verdict: Reviewed

---
Note:

The agent can sometimes produce false positives although often its
findings are genuine. If you find issues with the review, please
comment this email or ignore the suggestions.

Regards,
LTP AI Reviewer