Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "prototypes: xci: user-vars: Move root directory away from /opt"
  - prototypes: xci: user-vars: Move root directory away from /opt

    Having everything in the /opt implies root privileges. However, xci
    should work as normal user and as such we use the /tmp directory as
    the root directory.

    Change-Id: I985ded289208e1de53ad0ba878afd5bfd745c3fd
    Signed-off-by: Markos Chandras <mchandras@suse.de>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index d54e906..f2bbbd9 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit d54e906bc7b46f051332153e8ec37e8c3f435548
+Subproject commit f2bbbd939b4209e9f24f1ebd9d90116fd441b065