Update git submodules

* Update docs/submodules/yardstick from branch 'stable/euphrates'
  - Change 'SUCCESS' to 'PASS' when report to MongoDB

    JIRA: YARDSTICK-822

    To keep consistent with other testing project, we need to
    change 'SUCCESS' to 'PASS', 'FAILED' to 'FAIL'.

    Change-Id: I392e4dc6dd2e028cd43cba0d1bf8ee04618326d7
    Signed-off-by: chenjiankun <chenjiankun1@huawei.com>
    (cherry picked from commit f4680c872fbb34816d809c41852740f5cb960fd1)

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 4e79101..c69a715 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 4e791018445af16c68ee0572935b16fd8819d5ec
+Subproject commit c69a7153e498fb2cb6510d728d060f1f123e8dbd