vlib: add flag to explicitelly mark nodes which can init per-node packet trace

Type: feature

Change-Id: I913f08383ee1c24d610c3d2aac07cef402570e2c
Signed-off-by: Damjan Marion <damarion@cisco.com>
diff --git a/src/vlib/handoff_trace.c b/src/vlib/handoff_trace.c
index 7a67438..fcb514b 100644
--- a/src/vlib/handoff_trace.c
+++ b/src/vlib/handoff_trace.c
@@ -79,6 +79,7 @@
 VLIB_REGISTER_NODE (handoff_trace_node, static) =
 {
   .name = "handoff_trace",
+  .flags = VLIB_NODE_FLAG_TRACE_SUPPORTED,
   .function = handoff_trace_node_fn,
   .vector_size = sizeof (u32),
   .format_trace = format_handoff_trace,