Merge "Revert "Remove requirement that fsv_meta file is next to its inp...""...

  if not output_file:

    output_file = input_file + '.fsv_meta'

  if output_file != args.input + '.fsv_meta':

    sys.exit('When generating .fsv_meta files for symlinks, we assume that all fsv_meta files '

      'are named the same as the file they protect, just with the .fsv_meta suffix appended. '

      'We require that all .fsv_meta files follow this convention regardless of if it\'s a link or '

      'not. However {args.input} had a different output file: {args.output}')

  # remove the output file first, as switching between a file and a symlink can be complicated

  try:

    os.remove(output_file)