xen_disk: remove use of grant map/unmap

Now that the (native or emulated) xen_be_copy_grant_refs() helper is
always available, the xen_disk code can be significantly simplified by
removing direct use of grant map and unmap operations.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
1 file changed