zebra: fix route deletion during zebra shutdown

Restore the order of execution in zebra's main thread:
  vrf_terminate();
  zebra_dplane_finish();
  zebra_dplane_shutdown();
changed in commit 3b0e170.

  vrf_terminate() enqueues routes for deletion in dplane thread.
  zebra_dplane_shutdown() effectively forces dplane thread
to immediately cease and join (leaving unprocessed routes), while
  zebra_dplane_finish() has a condition that prevents
zebra_dplane_shutdown() from running until all routes queued for
dplane thread have been deleted.

Signed-off-by: Alexander Skorichenko <[email protected]>

zebra/main.c

@@ -204,6 +204,8 @@ static void sigint(void)
 
 	list_delete(&zrouter.client_list);
 
+	vrf_terminate();
+
 	/* Indicate that all new dplane work has been enqueued. When that
 	 * work is complete, the dataplane will enqueue an event
 	 * with the 'finalize' function.
@@ -219,8 +221,6 @@ void zebra_finalize(struct event *dummy)
 {
 	zlog_info("Zebra final shutdown");
 
-	vrf_terminate();
-
 	/*
 	 * Stop dplane thread and finish any cleanup
 	 * This is before the zebra_ns_early_shutdown call