Update git submodules

* Update docs/submodules/releng from branch 'master'
  - [Functest] Fix the issue that no return_value exists

    Save the execution return code to file before exiting

    Change-Id: I73692754b4c4c4b584d5918db7ce446bad931920
    Signed-off-by: helenyao <yaohelan@huawei.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index c08f0ef..30c08f9 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit c08f0ef55c70d61aa45c6268f2ab88bb4b446c28
+Subproject commit 30c08f92e136ac84fbc05d1cadf78c2c80ddd000