Update git submodules

* Update docs/submodules/vswitchperf from branch 'master'
  - scapy: Fix scapy import in Xena

    Remove unnecessary scapy import, which is causing pylint error
    with recent pylint version.

    JIRA: VSPERF-566

    Change-Id: I082de0e93242486248beaed6822a8d0f30fff7e5
    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>

diff --git a/docs/submodules/vswitchperf b/docs/submodules/vswitchperf
index a87a769..ba48693 160000 (submodule)
--- a/docs/submodules/vswitchperf
+++ b/docs/submodules/vswitchperf
@@ -1 +1 @@
-Subproject commit a87a7696e58082b10fadef24176d53ebc67f3bd5
+Subproject commit ba486932a77eb7b1ae2f1fd6b3e231df925887e7