This reverts commit 04d81227960b ("vhost: workaround MQ fails to
startup").
As agreed when this workaround was introduced, it can be reverted
as Qemu v2.10 that fixes the issue is now out.
The reply-ack feature is required for vhost-user IOMMU support.
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: Yuanhan Liu <yliu@fridaylinux.org>