vfio: Add Error** argument to .get_dirty_bitmap() handler

Let the callers do the error reporting. Add documentation while at it.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Avihai Horon <avihaih@nvidia.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
5 files changed