Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Fix _do_execute() return code in vping_ssh

    Change-Id: I781e51bb56f6cdac8b347e7fd85e70c07eb69e23
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index ceaea7f..30e4106 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit ceaea7f0cb95bce7f71d29dff71d58654cf0e700
+Subproject commit 30e4106b56608595885e1b46ad4b668866ab9426