ide/atapi scsi-disk: Make monitor eject -f, then change work

ide/atapi scsi-disk: Make monitor eject -f, then change work

change fails while the tray is locked by the guest.  eject -f forces
it open and removes any media.  Unfortunately, the tray closes again
instantly.  Since the lock remains as it is, there is no way to insert
another medium unless the guest voluntarily unlocks.

Fix by leaving the tray open after monitor eject.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>