Update git submodules

Update git submodules

* Update docs/submodules/vswitchperf from branch 'master'
  - Merge "xena_verify: Add final verification option to Xena"
  - xena_verify: Add final verification option to Xena

    Adds final verification option to Xena traffic generator
    inside VSPerf. Works by running the Xena2544.exe again
    after the initial run is complete with modified values
    inside the json file. If the final verify fails it will
    revert the settings and continue the in a pattern based
    on if the smart search is enabled.

    JIRA: VSPERF-506

    Change-Id: Ic272628c489b88989f67549bd020af7354dc9b91
    Signed-off-by: Christian Trautman <ctrautma@redhat.com>