qmp: add 'busy' member to BlockJobInfo Because pausing a job is asynchronous, we need to know whether it has completed. This is described by the "busy" field of BlockJob; copy it to BlockJobInfo. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>