xen: Log errno rather than return value

xen_modified_memory() sets errno to communicate what went wrong so log
this rather than the return value which is not interesting.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
1 file changed