Update git submodules

* Update docs/submodules/vswitchperf from branch 'master'
  - Merge "xena_pairs: Add pairs topology for 2544 testing"
  - xena_pairs: Add pairs topology for 2544 testing

    Add xena pairs topology and port removal options for JSON
    files with RFC2544 testing.  Refactored JSON code for
    better expansion later.

    Resolved pathing issues related to previous patch allowing
    for execution of VSPerf from any directory.

    JIRA: VSPERF-502

    Change-Id: Ida60c1223ae0f45f8879351770ab7fdce859b59b
    Signed-off-by: Christian Trautman <ctrautma@redhat.com>

diff --git a/docs/submodules/vswitchperf b/docs/submodules/vswitchperf
index 03f38e3..6139a65 160000 (submodule)
--- a/docs/submodules/vswitchperf
+++ b/docs/submodules/vswitchperf
@@ -1 +1 @@
-Subproject commit 03f38e3c9804f9c5a053a7a3b2c79381fe0deb68
+Subproject commit 6139a65e7100a46a557a70a077e04cffdbb54223