Update git submodules

* Update docs/submodules/samplevnf from branch 'master'
  - Adding app version display

    Change-Id: I366d915a05f58c5653de89c1c59ebd180904e080
    Signed-off-by: Deepak S <deepak.s@linux.intel.com>

diff --git a/docs/submodules/samplevnf b/docs/submodules/samplevnf
index 039ac41..2a738a1 160000 (submodule)
--- a/docs/submodules/samplevnf
+++ b/docs/submodules/samplevnf
@@ -1 +1 @@
-Subproject commit 039ac41531956a733ed96f7c715ed072e724e0df
+Subproject commit 2a738a1538bec699534c17d1801bd33f20dafda6