Fix: Assert in Cycles multi-device OIDN check

Co-authored-by: Brecht Van Lommel <brecht@blender.org>
Pull Request: https://projects.blender.org/blender/blender/pulls/119267

intern/cycles/integrator/denoiser.cpp

@@ -48,7 +48,9 @@ unique_ptr<Denoiser> Denoiser::create(Device *path_trace_device, const DenoisePa
 
 DenoiserType Denoiser::automatic_viewport_denoiser_type(const DeviceInfo &path_trace_device_info)
 {
-  if (OIDNDenoiserGPU::is_device_supported(path_trace_device_info)) {
+  if (path_trace_device_info.type != DEVICE_CPU &&
+      OIDNDenoiserGPU::is_device_supported(path_trace_device_info))
+  {
     return DENOISER_OPENIMAGEDENOISE;
   }
   else if (!Device::available_devices(DEVICE_MASK_OPTIX).empty()) {

intern/cycles/integrator/denoiser_oidn_gpu.cpp

@@ -36,6 +36,8 @@ bool OIDNDenoiserGPU::is_device_supported(const DeviceInfo &device)
         return true;
       }
     }
+
+    return false;
   }
 
   int device_type = OIDN_DEVICE_TYPE_DEFAULT;