Use x86's __inttype macro instead of using the typeof(x-x) trick to
generate a suitable integer size type.  This avoids a sparse warning
when examining the x-x type with a bitwise type.
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NChris Metcalf <cmetcalf@ezchip.com>