ping: install ndnping from ndn-tools

refs #2836

Change-Id: I650680a388801fec6a11ec55a5d6d2d13da2f737
diff --git a/test_nfdc/nfdc-test.sh b/test_nfdc/nfdc-test.sh
index 9c49198..862115c 100755
--- a/test_nfdc/nfdc-test.sh
+++ b/test_nfdc/nfdc-test.sh
@@ -89,7 +89,7 @@
   # Invoke nfdc to choose BroadcastStrategy for ndn:/ namespace.
   nfdc set-strategy ndn:/ ndn:/localhost/nfd/strategy/broadcast
 
-  ndnping ndn:/test-nfdc -c $NUM_OF_PINGS
+  ndnping -c $NUM_OF_PINGS ndn:/test-nfdc
 
   check_nfd_status_counters $faceIdTcp4 tcp4://$IP4_B1 out $NUM_OF_PINGS
   check_nfd_status_counters $faceIdTcp6 tcp6://[$IP6_B1] out $NUM_OF_PINGS