iommu/vt-d: Make use of domain_alloc and domain_free
iommu/vt-d: Make use of domain_alloc and domain_free

Get rid of domain_init and domain_destroy and implement
domain_alloc/domain_free instead.

Reviewed-by: Alex Williamson <7469de9b95ba379e2656fa9677689657c47a7690@redhat.com>
Signed-off-by: Joerg Roedel <61aff96566804ea1da8a65de5bcc892ce07caceb@suse.de>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs