Stat segment / client: show run" works now

Seems to have minimal-to-zero performance consequences. Data appears
accurate: result match the debug CLI output. Checked at low rates, 27
MPPS sprayed across two worker threads.

Change-Id: I09ede5150b88a91547feeee448a2854997613004
Signed-off-by: Dave Barach <dave@barachs.net>
diff --git a/src/vat/vat.h b/src/vat/vat.h
index 19796b9..c9384a1 100644
--- a/src/vat/vat.h
+++ b/src/vat/vat.h
@@ -129,7 +129,7 @@
 
   /* Graph node table */
   uword *graph_node_index_by_name;
-  vlib_node_t **graph_nodes;
+  vlib_node_t ***graph_nodes;
 
   /* ip tables */
   ip_details_t *ip_details_by_sw_if_index[2];