Update git submodules

Update git submodules

* Update docs/submodules/samplevnf from branch 'master'
  - Merge "UDP_Replay: rte_hash_lookup_multi renamed to rte_hash_lookup_bulk"
  - UDP_Replay: rte_hash_lookup_multi renamed to rte_hash_lookup_bulk

    JIRA: SAMPLEVNF-20

    The function name rte_hash_lookup_multi() is changed to
    rte_hash_lookup_bulk() in DPDK version 16.11 and onwards.

    This fix supports DPDK16.04, 16.11 and onwards and required for
    DPDK17.05 migration.

    Change-Id: I01f2145919768b5146116e67d7f349a5b039251c
    Signed-off-by: Anand B Jyoti <anand.b.jyoti@intel.com>