fix ONNXRuntime cuda test bug (open-mmlab#438)

Author: NagatoYuki0943

mmdeploy/codebase/mmdet/deploy/object_detection_model.py

@@ -208,6 +208,7 @@ def forward(self, img: Sequence[torch.Tensor], img_metas: Sequence[dict],
         rescale = kwargs.get('rescale', True)
         for i in range(batch_size):
             dets, labels = batch_dets[i], batch_labels[i]
+            dets = dets.to(device=torch.device(self.device))
             if rescale:
                 scale_factor = img_metas[i]['scale_factor']