When swapchain is created in windowed mode, and then enter fullscreen
via Alt+Enter. Calling d3d11_swapchain_GetFullscreenState will return
a null output because swapchain->target wasn't initialized.
Signed-off-by: Zhiyi Zhang <zzhang@codeweavers.com>
Signed-off-by: Henri Verbeet <hverbeet@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>