Remove dead file-backup code
- fsmVerify() never ever returns 0 for regular files because of
multiple hacks in how this all "works": on install, we skip stat()
but claim disk checked and file not existing, so fsmVerify() returns
early. Good thing it does too, as otherwise it would remove the
file we were supposed to be saving here. The actual %config backup
occurs in fsmCommit(): regular files are first installed with a
temporary suffix and at "commit" time we decide whether it needs
backing up or not (involving several other hacks...)