Switching a block job to some states (e.g. QEMU_BLOCKJOB_STATE_READY)
might not require a job, thus if it will become ready asynchronously we
should not overwrite the state any more.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>