rtld: Compress FreeBSD CVSIDs

rtld: Compress FreeBSD CVSIDs

The FreeBSD repository is still handled by CVS, but its converted to
Subversion and from that, git.  Neither the svn nor git version feature
expanded $FreeBSD$ tags.  The only way to get this is to pull directly
from CVS which isn't convenient.

In the case of a few files, the only difference between the DragonFly
version and the FreeBSD version is the CVS tag.  As the main development
of rtld is happening on FreeBSD and since I've started collaborating
with FreeBSD developers on new dynamic linker features, we want to
actively keep our linkers synchronized.  Compressing the FreeBSD CVSID
tags makes that easier for me, the only person currently maintaining
the dynamic linker.  The usually-wrong expanded CVS tag wasn't providing
any useful information to me either.