Update git submodules

* Update docs/submodules/yardstick from branch 'stable/danube'
  - Merge "operation_general: fix logging to use %s" into stable/danube
  - operation_general: fix logging to use %s

    Change-Id: I1b37cbf07e8858ca3e75bb74c57fe84485ff4989
    Signed-off-by: Ross Brattain <ross.b.brattain@intel.com>
    (cherry picked from commit 37f600566c56542999529da47299c4caf54d073a)

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 4738c37..edfaab0 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 4738c37f004d6a4e3c60cff5941b91ba162fbfde
+Subproject commit edfaab003e182b500b88adbac94625e9053455fb