message: Fix comment in script
diff: #=============================================================================
  # Change the copyright date in all files that contain the text
  -# "the RAJAPerf/COPYRIGHT file", which is part of the copyright statement
  +# "the RAJAPerf/LICENSE file", which is part of the copyright statement
  # at the top of each RAJA file. We use this to distinguish RAJA files from
  # that we do not own (e.g., other repos included as submodules), which we do
  # not want to modify. Note that this file and *.git files are omitted
  