duplicate doxygen entries for drmemtrace functions

The doxygen output for drmemtrace seems to create two identical entries for each function.
See initialize(), get_error_string(), etc.: https://dynamorio.org/docs/classanalysis__tool__t.html#af926d04a522915a32a9186297564eec2

Start with the linked Doxygen page and compare the entries for initialize(), get_error_string(), and the other drmemtrace functions. Trace those functions back to their documented declarations or definitions and identify why each appears twice. Done means the generated Doxygen output contains one entry per function.

Written by the indexing model from the issue text.