maint: remove unused imports from bin/nova-*

Change-Id: I80b58ac41bbb0517221d5fd5ba9938f2b7836779
Return dest_check_data as expected by the Scheduler

the scheduler driver expects data in return when
calling compute_rcp.check_can_live_migrate_destination
in method 'schedule_live_migration'.

In turn check_can_live_migrate_destination calls
check_can_live_migrate_source that also expects data
returned from the driver.

Fixes bug #1118491

Change-Id: I3dbfa716d5d9bc849c1f67005e7bb1b8ba1ccd30
Merge "maint: remove unused imports from bin/nova-*"
Merge "Return dest_check_data as expected by the Scheduler"