RTPStream: Deduplicate logic for audio/video debug files

[orgads]

No description provided.

[lemenkov]

Overall looks good. perhaps we could slightly improve it (in a separate PR) - Claude insists there is a TOCTOU issue here:

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Race condition (theoretical, not practical)

printHex() and printVector() check fp before acquiring the mutex but use it after:

if (!fp || !note || !string || !rtpcheck_debug)  // no lock
    return;
std::lock_guard lock(mutex);
fprintf(fp, ...);  // fp could be null if close() ran in between

In practice this can't fire because close() is only called from rtpstream_shutdown() after all threads are joined. But it's technically a TOCTOU race. A quick if (!fp) return; after the lock acquisition would make it bulletproof.

Same pattern in open() and close() — the outer if (fp) is unsynchronized. Again harmless in practice since open/close don't race with each other given SIPp's lifecycle.

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[orgads]

@lemenkov I prefer rebase/squash over merge. Disabled merge in settings. If you dislike it, let's discuss.