Update git submodules

Update git submodules

* Update docs/submodules/samplevnf from branch 'master'
  - Workaround DPDK net/virtio queue setup issue

    JIRA: SAMPLEVNF-127

    PROX was crashing in the VM with vector mode enabled and multiple OVS
    queues. This was not really a PROX bug, but a DPDK issue, which has been
    fixed by DPDK commit https://git.dpdk.org/dpdk/commit/?id=efc83a1e7fc3
    This "net/virtio: fix queue setup consistency" is included in DPDK 17.11
    and subsequent versions, and has been backported into:
    - DPDK 16.11.4:
      https://git.dpdk.org/dpdk-stable/commit/?h=16.11&id=516447a5056c
    - DPDK 17.08.1:
      https://git.dpdk.org/dpdk-stable/commit/?h=17.08&id=907fe4fc263e

    This means the fix is not included into any DPDK 17.02.x used by NSB.
    Fortunately, a simple workaround consists of calling
    rte_eth_tx_queue_setup() before rte_eth_rx_queue_setup().

    This change implements this simple workaround, in order to make PROX
    work, even with unfixed DPDK versions.

    Change-Id: I818e9bb812babe023c6b7225c8b9769a359d9bec
    Signed-off-by: Patrice Buriez <patrice.buriez@intel.com>