session: fix app attach on error

Type: fix

Change-Id: I57b3c76515544ba3655690b37e0dacb47734ba6d
Signed-off-by: Nathan Skrzypczak <nathan.skrzypczak@gmail.com>
diff --git a/src/vnet/session/session_api.c b/src/vnet/session/session_api.c
index c17d98c..0b610f3 100755
--- a/src/vnet/session/session_api.c
+++ b/src/vnet/session/session_api.c
@@ -661,13 +661,12 @@
     }
 
 done:
-
-  ctrl_thread = vlib_num_workers ()? 1 : 0;
-  ctrl_mq = session_main_get_vpp_event_queue (ctrl_thread);
   /* *INDENT-OFF* */
   REPLY_MACRO2 (VL_API_APP_ATTACH_REPLY, ({
     if (!rv)
       {
+	ctrl_thread = vlib_num_workers ()? 1 : 0;
+	ctrl_mq = session_main_get_vpp_event_queue (ctrl_thread);
 	segp = a->segment;
 	rmp->app_index = clib_host_to_net_u32 (a->app_index);
 	rmp->app_mq = pointer_to_uword (a->app_evt_q);