Cleanup: Fix Compilation Warning

On Mac there is a compilation warning when compiling without support
for open image denoising.

Pull Request: https://projects.blender.org/blender/blender/pulls/108882

source/blender/compositor/operations/COM_DenoiseOperation.cc

@@ -32,16 +32,16 @@ class DenoiseFilter {
 #ifdef WITH_OPENIMAGEDENOISE
   oidn::DeviceRef device_;
   oidn::FilterRef filter_;
-#endif
   bool initialized_ = false;
+#endif
 
  public:
+#ifdef WITH_OPENIMAGEDENOISE
   ~DenoiseFilter()
   {
     BLI_assert(!initialized_);
   }
 
-#ifdef WITH_OPENIMAGEDENOISE
   void init_and_lock_denoiser(MemoryBuffer *output)
   {
     /* Since it's memory intensive, it's better to run only one instance of OIDN at a time.