CBQE-0: fix in perf and logs in install.py

Change-Id: Iae39422802824bc44c3d79ff2d218689fd883f3a
Reviewed-on: http://review.couchbase.org/35071
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>