Update git submodules

* Update docs/submodules/vswitchperf from branch 'master'
  - rhel_epel_fix: Fix installation of spel for sshpass

    RHEL does not have an epel-release package available from default repos.
    Removes this install to use fedora epel release to allow sshpass to install
    correctly.

    Change-Id: Ie313857420cb4eb2342128b5d11e769670ae70a0
    Signed-off-by: Christian Trautman <ctrautma@redhat.com>

diff --git a/docs/submodules/vswitchperf b/docs/submodules/vswitchperf
index a965560..3c27944 160000 (submodule)
--- a/docs/submodules/vswitchperf
+++ b/docs/submodules/vswitchperf
@@ -1 +1 @@
-Subproject commit a9655607f7618fd392cf719e8d9ea2dbf6c8dd1c
+Subproject commit 3c2794471edd1a931dfdac31a32a4087d40f5289