Update git submodules

* Update docs/submodules/samplevnf from branch 'master'
  - Fixed issues with the pkt_size command

    Fixed issues with pkt_size. For a 64 byte packet, we need to issue
    pkt_size <core> <task> 60
    4 extra bytes will be calculated and added automatically by PROX
    Also added the missing irq.test and irq.cfg files
    Added support for OpenStack systems not using floating IP addresses

    Change-Id: I05d775eb858a58dd349ea370a0e34ac6448590c9
    Signed-off-by: Luc Provoost <luc.provoost@intel.com>

diff --git a/docs/submodules/samplevnf b/docs/submodules/samplevnf
index d29f8fa..7fa9c0b 160000 (submodule)
--- a/docs/submodules/samplevnf
+++ b/docs/submodules/samplevnf
@@ -1 +1 @@
-Subproject commit d29f8fa251540b48371f76e47ddba6315607d192
+Subproject commit 7fa9c0b506709a683ec8984e19e9ba9deb27e021