eclass-overlay: fix comments in preserve group

BUG=None
TEST=./build_image

Change-Id: Ic815ecf4ee4dd0a8445019fcec8e50c2c1930341
Reviewed-on: https://chromium-review.googlesource.com/1582360
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Leo Lai <cylai@google.com>
Reviewed-by: John  Chen <zuan@chromium.org>
Reviewed-by: Wei-Cheng Xiao <garryxiao@chromium.org>
1 file changed
tree: 25ee67af8a8f5a4f2b7b8df90dd985d735f0b3a1
  1. PRESUBMIT.cfg
  2. eclass/
  3. metadata/
  4. profiles/