Update git submodules

Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Only Submit Security Scan Results that Exist

    When anteater runs it generates a shortlog containing any errors that
    were encountered during it's run.

    If no errors exist it will still create an empty file 'shortlog'. A
    review containing no content will be attempt to be posted and fail with:

      fatal: Argument "{COMMIT | CHANGE,PATCHSET}" is required

    Instead of attempting to post nothing, the job should just skip
    submitting a review.

    Change-Id: I3feacb15e47dea204783053b3e67a9aa81ba164d
    Signed-off-by: Trevor Bramwell <tbramwell@linuxfoundation.org>