packet-gvsp.c: Fix license; Remove unneeded code from proto_reg_handoff..(); adjust whitespace.

Change-Id: I24a9033bbed3d50daf886f3d00239c1580894c35
Reviewed-on: https://code.wireshark.org/review/4670
Reviewed-by: Bill Meier <wmeier@newsguy.com>