Fix DLFG RecreateSwapchain livelock

Reset m_lastPresentStatus on DLFG recreateSwapChain

- There existed a livelock in D3D9SwapChainEx::PresentImage when DLFG was enabled
  - If the DLFG Presenter fails to acquireNextImage, we enter a loop attempting to RecreateSwapChain
  - In that loop, the next call to acquireNextImage early-outs on a failed previous present status
  - Loop then reruns because the present status is kept as a failing
- Fix: DLFG RecreateSwapchain needs to reset the present status to success to break the loop

See merge request lightspeedrtx/dxvk-remix-nv!1172

Author: nv-nfreybler

src/dxvk/rtx_render/rtx_dlfg.cpp

@@ -220,6 +220,10 @@ namespace dxvk {
     if (res != VK_SUCCESS) {
       return res;
     }
+    
+    // Reset present status since we recreated the swapchain. This ensures we try to acquire
+    // during the next present instead of returning a stale error value.
+    m_lastPresentStatus = VK_SUCCESS;
 
     createBackbuffers();
     return res;