vmwgfx: Make present readbacks not cross scanout bounding box boundaries
vmwgfx: Make present readbacks not cross scanout bounding box boundaries

Signed-off-by: Thomas Hellstrom <a26490dfbee4be3d38287ad6448444504f58193c@vmware.com>

dezelin/xf86-video-vmware,dezelin/xf86-video-vmware,dezelin/xf86-video-vmware