Fixes to allow running p4 trellis scenario

Change-Id: I4882668168521b9119692ecd696189b2b8d5f9de
(cherry picked from commit a61ba5792d9e7a25d3446f37179fbf13ac152098)
diff --git a/tools/test/scenarios/net-setup-trellis-p4.xml b/tools/test/scenarios/net-setup-trellis-p4.xml
index e4bc2ee..f27263a 100644
--- a/tools/test/scenarios/net-setup-trellis-p4.xml
+++ b/tools/test/scenarios/net-setup-trellis-p4.xml
@@ -86,7 +86,7 @@
               exec="onos-mininet wait 10"/>
 
         <!-- clean up local routing repo if necessary -->
-        <step name="Trellis-Net-P4-Setup.Clean-Routing"
+        <step delay="10" name="Trellis-Net-P4-Setup.Clean-Routing"
               requires="Trellis-Net-P4-Setup.Start-Mininet"
               exec="onos-clean-routing ${routing_root}"/>
     </group>