Fix devstack plugin to stop octavia processes

The octavia devstack plugin was missing the methods to actually stop
the devstack processes on devstack shutdown.  This patch makes the
appropriate devstack function calls to stop the processes.

Change-Id: I0a7b4c5b2bd3664fd113d588a533c0d4e16493e8

devstack/plugin.sh

@@ -463,6 +463,14 @@ function octavia_start {
 
 function octavia_stop {
     # octavia-specific stop actions
+    if [[ "$OCTAVIA_USE_MOD_WSGI" == "True" ]]; then
+        _stop_octavia_apache_wsgi
+    else
+        stop_process $OCTAVIA_API
+    fi
+    stop_process $OCTAVIA_CONSUMER
+    stop_process $OCTAVIA_HOUSEKEEPER
+    stop_process $OCTAVIA_HEALTHMANAGER
 
     # Kill dhclient process started for o-hm0 interface
     pids=$(ps aux | awk '/o-hm0/ { print $2 }')
@@ -472,9 +480,6 @@ function octavia_stop {
             sudo ip link del o-hm0
         fi
     fi
-    if [[ "$OCTAVIA_USE_MOD_WSGI" == "True" ]]; then
-        _stop_octavia_apache_wsgi
-    fi
 }
 
 function octavia_configure_common {