hw/xwin: Move reshape code from winUpdateWindowPosition() to the map event handler

hw/xwin: Move reshape code from winUpdateWindowPosition() to the map event handler

Move reshape code, which was only used when handling a map event, from
winUpdateWindowPosition(), to put it explicitly in the map event handler.

Remove 'reshape' parameter from winUpdatePosition().

(Note that there's no handling of the ShapeNotify event to notice when the
window shape changes, instead we hook the screen SetShape procedure and reshape
the native window then)

Signed-off-by: Jon TURNEY <jon.turney@dronecode.org.uk>
Reviewed-by: Colin Harrison <colin.harrison@virgin.net>