Periodic task _cleanup_running_deleted_instances() looks for orphaned
and running instances on hypervisor that should be deleted.
The problem is it checks if running instance has the same
hypervisor defined as it is in nova database.
In bug #1285000 it has been found that removing instance during
its migration could lead to abandon instance files on destination
host.
This change removes host filter in _running_deleted_instances() to
find also orphaned instances that are running on 'post migration'
destination host.
Change-Id: Idd1b58b85329b8e021eba4bc27f577af1b3338f4
Partial-Bug: #1285000