Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Clean jjb/functest/functest-k8.sh

    It removes lots of obsolete or useless logics.

    Change-Id: I64a85e813aab520de9d0d77e26a7c8becaa0950b
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 702035c..6cf4b53 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 702035c04ad807206a1649edfb24b5cc9caac15d
+Subproject commit 6cf4b53992d9b60ec8c67f82668abdd7a0afa115