wined3d: Respect the BO address offset when uploading data from the CPU in wined3d_texture_gl_download_data_slow_path().
Signed-off-by: Zebediah Figura <zfigura@codeweavers.com>
Signed-off-by: Henri Verbeet <hverbeet@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>