d3d11: fix ID3D11Device leak in UWP mode

The ID3D11DeviceContext_GetDevice() already gets a reference to the device.
We don't do add one manually.

Author: robUx4

modules/video_output/win32/direct3d11.c

@@ -233,7 +233,6 @@ static int OpenCoreW(vout_display_t *vd)
     sys->d3d_dev.d3dcontext    = d3dcontext;
     sys->d3d_dev.feature_level = ID3D11Device_GetFeatureLevel(sys->d3d_dev.d3ddevice );
     IDXGISwapChain_AddRef     (sys->dxgiswapChain);
-    ID3D11Device_AddRef       (sys->d3d_dev.d3ddevice);
     ID3D11DeviceContext_AddRef(sys->d3d_dev.d3dcontext);
 
     sys->sys.pf_GetRect = GetRect;