Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "code inspection fixes: test_pktgen"
  - code inspection fixes: test_pktgen

    Change-Id: I05cb069984b7674924cfcb1ed023048c0aa0c444
    Signed-off-by: Ross Brattain <ross.b.brattain@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 6546e04..c26a006 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 6546e0467013abd5fff236b6e9d7137b292a4d4e
+Subproject commit c26a006b489fcf61948a97bb18d39b7275c68d27