Remove dead file-backup code

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...)