Update git submodules

* Update docs/submodules/yardstick from branch 'stable/euphrates'
  - Merge "KVMFORNFV: Reverting LiveMigration changes" into stable/euphrates
  - KVMFORNFV: Reverting LiveMigration changes

    This patch consists of reverting the changes of patch 45227 and
    incudes redirecting the console output of the LiveMigration
    execution to /dev/null as the stdout contains only the statistics,
    i.e., totaltime, downtime and setuptime.

    This reverts commit 5a1f65d3e7d67488ee6f558dccfa5ca5581ddb65.

    Change-Id: I252b5a4045657cfa8362e9aae755249480cd3b77
    Signed-off-by: Navya <navyax.bathula@intel.com>
    (cherry picked from commit 3ca70b916c386b7ec4d9a7f2f9bb6fec2e917785)

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 102e352..4f0b229 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 102e3528ba4d7b8c566c1304192c4036f2a94f8f
+Subproject commit 4f0b2293ce25d8311d352bc4f10708d6a1e00c79