PIDL (DCERPC winreg): enhance dissector

* Fix PIDL generator for NOEMIT Element (fix -Wunused-function for DCERPC winreg dissector)
* Fix indent (use tabs)
* Remove DCERPC winreg dissector from DIRTY list

Change-Id: I5d16cbfe8481a5e5f7e5df9b51735c93ae4375a7
Reviewed-on: https://code.wireshark.org/review/4322
Reviewed-by: Michael Mann <mmann78@netscape.net>