CBQE-0: fix for busy workload monitor

we should sleep no matter what when monitoring for
workload to finish

Change-Id: Id2b01b1d53df32e2e0cbe9ad0fab85bea1d944f5
Reviewed-on: http://review.couchbase.org/25369
Reviewed-by: Tommie McAfee <tommie@couchbase.com>
Tested-by: Tommie McAfee <tommie@couchbase.com>