Update git submodules

Update git submodules

* Update docs/submodules/vswitchperf from branch 'master'
  - Merge "teststeps: Improvements and bugfixing of teststeps"
  - teststeps: Improvements and bugfixing of teststeps

    This patch introduces several improvements and small bugfixes
    of teststeps. These changes were identified during implementation
    of OVS/DPDK regression tests.

    Patch content:
    * teststeps: step aliases were implemented
    * teststeps: improved filtering by regex for any step, which returns string
      or list of stings; filter will process all lines
    * teststeps: support for log object
    * teststeps: support for trafficgen get_results call
    * teststeps: configurable suppression of step validation
    * trafficgen: remove old results before traffic is executed
    * trafficgen: support for flow control on/off (IxNet)
    * trafficgen: support for configurable learning frames (IxNet)
    * trafficgen: support for runtime changes of TRAFFICGEN_PKT_SIZES, _DURATION
      and _LOSSRATE
    * vnf: flush pexpect output of previous commands
    * vnf: use execute_and_wait() to ensure correct cmds order
    * vnf: dpdk vHost User interface name set according to its type,
      e.g. dpdkvhostuserclient
    * vswitch: support for OVS restart
    * decap: simplify configuration of tunneling decapsulation tests
    * settings: values of all configuration options are restored after TC execution
    * modified formatting of test description used by --list
    * testcase name and description is logged before its execution
    * small bugfixes

    JIRA: VSPERF-539

    Change-Id: I550ba0d897ece89abd3f33d6d66f545c4d863e7b
    Signed-off-by: Martin Klozik <martinx.klozik@intel.com>
    Reviewed-by: Al Morton <acmorton@att.com>
    Reviewed-by: Christian Trautman <ctrautma@redhat.com>
    Reviewed-by: Sridhar Rao <sridhar.rao@spirent.com>
    Reviewed-by: Trevor Cooper <trevor.cooper@intel.com>