vlib: Fix packet tracing

Type: fix
Fixes: 99536f4

Change-Id: Ica230ec9fa7f6fd36e2754e8b0b9db555460ca55
Signed-off-by: Neale Ranns <nranns@cisco.com>
diff --git a/src/vlib/trace_funcs.h b/src/vlib/trace_funcs.h
index d0eeb29..257c3a3 100644
--- a/src/vlib/trace_funcs.h
+++ b/src/vlib/trace_funcs.h
@@ -145,7 +145,7 @@
 				     (struct vlib_trace_main_t *) tm);
     }
 
-  //vlib_trace_next_frame (vm, r, next_index);
+  vlib_trace_next_frame (vm, r, next_index);
 
   pool_get (tm->trace_buffer_pool, h);