Update git submodules

* Update docs/submodules/nfvbench from branch 'master'
  - Update with section on cleanup script

    Change-Id: Ib7185ac3e7643dbafb30bd0a57bc7cc717638ab6
    Signed-off-by: ahothan <ahothan@cisco.com>

diff --git a/docs/submodules/nfvbench b/docs/submodules/nfvbench
index 70e642c..0549282 160000 (submodule)
--- a/docs/submodules/nfvbench
+++ b/docs/submodules/nfvbench
@@ -1 +1 @@
-Subproject commit 70e642c54ffbf50e860e87de3bdcb8fa65d8bac4
+Subproject commit 054928298b635893db73e2e827605d4a3896969e