Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "bug-fix: delete directory created by root for workspace cleanup"
  - bug-fix: delete directory created by root for workspace cleanup

    JIRA: RELENG-311

    RT

    Change-Id: Id6c5306ef02a3c02c270ef0e548c41dde6d1b8b4
    Signed-off-by: Yang Yu <Gabriel.yuyang@huawei.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index fb51c4a..eb39f29 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit fb51c4a4d5cbebda0bd20e19f538811e314855ee
+Subproject commit eb39f29dd8367c761eae9b00a889cfea498f0550