Fix NULL pointer dereference on IOMMU domain destruction that happens
because clients list is being iterated unsafely and its elements are
getting deleted during the iteration.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>