[d3d9] Synchronize with presentation in D3D9SwapChainEx::Reset

Otherwise, the subsequent patches would break if Reset is called
while there's still a frame in flight.

src/d3d9/d3d9_swapchain.cpp

@@ -289,6 +289,7 @@ namespace dxvk {
           D3DDISPLAYMODEEX*      pFullscreenDisplayMode) {
     auto lock = m_parent->LockDevice();
 
+    this->SynchronizePresent();
     this->NormalizePresentParameters(pPresentParams);
 
     m_dirty    |= m_presentParams.BackBufferFormat   != pPresentParams->BackBufferFormat