Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "fix ha issue when run tc050~tc054 in ci"
  - fix ha issue when run tc050~tc054 in ci

    JIRA: YARDSTICK-634

    Change-Id: I46681c7e8afe391eef9c5309470028167e911950
    Signed-off-by: rexlee8776 <limingjiang@huawei.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 1991dc9..6c9f795 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 1991dc99014359d15351f3da3eeaa6fc1348d632
+Subproject commit 6c9f7954aa9f1934618e880d86297de2b2365ab6