dense_node-itest: add extra log output
dense_node-itest: add extra log output

For yet-unexplained reasons, this itest still sometimes skips outputting
the expected 'Time spent bootstrapping tablets' log statement. This
commit simply adds a few extra log messages to help diagnose this next
time it occurs.

Change-Id: Ic967558e34a8db673a518c37afdb68d86262a443
Reviewed-on: http://gerrit.cloudera.org:8080/7775
Reviewed-by: Adar Dembo <866ca730bfc7f544e3ebce604ceeba4879f23df0@cloudera.com>
Tested-by: Kudu Jenkins

InspurUSA/kudu,andrwng/kudu,EvilMcJerkface/kudu,andrwng/kudu,helifu/kudu,helifu/kudu,InspurUSA/kudu,cloudera/kudu,andrwng/kudu,cloudera/kudu,InspurUSA/kudu,EvilMcJerkface/kudu,cloudera/kudu,EvilMcJerkface/kudu,helifu/kudu,andrwng/kudu,helifu/kudu,EvilMcJerkface/kudu,InspurUSA/kudu,EvilMcJerkface/kudu,cloudera/kudu,helifu/kudu,andrwng/kudu,InspurUSA/kudu,cloudera/kudu,helifu/kudu,andrwng/kudu,andrwng/kudu,helifu/kudu,InspurUSA/kudu,cloudera/kudu,andrwng/kudu,EvilMcJerkface/kudu,InspurUSA/kudu,cloudera/kudu,EvilMcJerkface/kudu,InspurUSA/kudu,cloudera/kudu,helifu/kudu,andrwng/kudu,EvilMcJerkface/kudu,InspurUSA/kudu,cloudera/kudu,helifu/kudu,EvilMcJerkface/kudu