Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Fix Yamllint Violations for jjb/cperf"
  - Fix Yamllint Violations for jjb/cperf

    JIRA: RELENG-254

    Change-Id: I8c644ac0bce05f66b1b878e39a00342c857d23f0
    Signed-off-by: Trevor Bramwell <tbramwell@linuxfoundation.org>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index f58cb46..c6e3a6c 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit f58cb46411aa9109c1f721fcf27650a92a1c8d4f
+Subproject commit c6e3a6c7b4791f7cfbe50cf93c6c955fecc9d747