Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Add check mode in Functest jjbs

    It allows checking one specific change on LF resources.
    It completes the two modes already defined: daily and gate.

    Change-Id: I7ccadf1ef07533bb549ee365b4f3deedd3d457fe
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index d20c5ac..c876505 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit d20c5ac0fbec72945f72df21a61d6da4c5d45bf2
+Subproject commit c8765055df82461e9210706d04f4a8d09a440d68