patch 8.1.1273: compiler warning in direct write code

Problem:    Compiler warning in direct write code.
Solution:   Add a type cast.
diff --git a/src/gui_dwrite.cpp b/src/gui_dwrite.cpp
index 3c477d0..8767dc1 100644
--- a/src/gui_dwrite.cpp
+++ b/src/gui_dwrite.cpp
@@ -949,7 +949,7 @@
 	    if (mDrawing)
 	    {
 		hr = mRT->EndDraw();
-		if (hr == D2DERR_RECREATE_TARGET)
+		if (hr == (HRESULT)D2DERR_RECREATE_TARGET)
 		{
 		    hr = S_OK;
 		    DiscardDeviceResources();