virtio-iommu: Fix migration regression

virtio-iommu: Fix migration regression

We also need to switch to the right address space on dest side
after loading the device status. DMA to wrong address space is
destructive.

Fixes: 3facd774962fd ("virtio-iommu: Add bypass mode support to assigned device")
Suggested-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Message-Id: <20220624093740.3525267-1-zhenzhong.duan@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>