It turns out it was actually dead code. The last remaining caller was
the cross-swapchain blit case but surface_blt_special() actually
rejected those (or any swapchain to swapchain blit).
Signed-off-by: Matteo Bruni <mbruni@codeweavers.com>
Signed-off-by: Henri Verbeet <hverbeet@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>