PIDL (DCERPC eventlog): enhance dissector

* Fix -Wunused-function (Add functions to eventlog.cnf with NOEMIT)
* Remove dissector DCERPC eventlog from DIRTY list

Change-Id: I29710ce4f548a6e4d9bf1dd6e652acf1eeaddf2c
Reviewed-on: https://code.wireshark.org/review/4324
Reviewed-by: Michael Mann <mmann78@netscape.net>