LNA: Return after unexpected permission callback

Port keeps outstanding Local Network Access permission requests in
permission_queries_. If a permission callback arrives after its query
was already removed, the iterator lookup returns end().

The code logged the unexpected callback and hit
RTC_DCHECK_NOTREACHED(), but release builds can continue after that
check. That allowed erase(end()) and then the moved callback path to
run with invalid state.

Return immediately after the DCHECK so debug behavior is unchanged,
while release builds stop before using the invalid iterator.

Bug: chromium:421223919
Change-Id: I0ebb5e122417181436eec70fa3bd429e289b958f
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/470400
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Harald Alvestrand <hta@webrtc.org>
Auto-Submit: Daniel.L (Byoungchan) Lee <daniel.l@hpcnt.com>
Cr-Commit-Position: refs/heads/main@{#47644}