stub_gnttab_mapv_batched should call gntmap_map_grant_refs
stub_gnttab_mapv_batched should call gntmap_map_grant_refs

Now that we've switched to an 'allocating' interface, we have to
implement both individual mapping and batch mapping.

Signed-off-by: David Scott <63c9eb0ea83039690fefa11afe17873ba8278a56@citrix.com>

mato/mirage-solo5,mato/mirage-solo5