vmware-vga: use vmsvga_verify_rect in vmsvga_update_rect

Switch vmsvga_update_rect over to use vmsvga_verify_rect.  Slight change
in behavior:  We don't try to automatically fixup rectangles any more.
In case we find invalid update requests we'll do a full-screen update
instead.

Cc: qemu-stable@nongnu.org
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Don Koch <dkoch@verizon.com>