log.h: help doxygen out a bit.

doxygen does a better job if you say function() rather than just function, and there were a couple of places that could use an explicit `{@link ...}`.

Change-Id: Ibdc3912abf2b90ba973374d843977e281e143725
GitOrigin-RevId: 07ec6369980a3b071c1357ab29125e5c032c171f