modify the model_split.py file

``` shell
python demo/top_down_img_demo.py configs/wholebody/2d_kpt_sview_rgb_img/topdown_heatmap/coco-wholebody/ViTPose_base_wholebody_256x192.py target/wholebody.pth  --img-root tests/data/coco/ --json-file tests/data/coco/test_coco.json --out-img-root vis_results
```
When I use the previous model_split.py, above command occurs error, and the modified version can work properly.

tools/model_split.py

@@ -40,7 +40,7 @@ def main():
             value = torch.cat([value, experts[key.replace('fc2.', f'experts.{target_expert}.')]], dim=0)
             new_ckpt['state_dict'][key] = value
 
-    torch.save(new_ckpt, os.path.join(args.targetPath, 'coco.pth'))
+    torch.save(new_ckpt, os.path.join(args.target, 'coco.pth'))
 
     names = ['aic', 'mpii', 'ap10k', 'apt36k','wholebody']
     num_keypoints = [14, 16, 17, 17, 133]
@@ -86,8 +86,19 @@ def main():
 
         for tensor_name in ['keypoint_head.final_layer.weight', 'keypoint_head.final_layer.bias']:
             new_ckpt['state_dict'][tensor_name] = new_ckpt['state_dict'][tensor_name][:num_keypoints[i]]
-
+
+        # remove unnecessary part in the state dict
+        for j in range(5):
+            # remove associate part
+            for tensor_name in weight_names:
+                new_ckpt['state_dict'].pop(tensor_name.replace('keypoint_head', f'associate_keypoint_heads.{j}'))
+        # remove expert part
+        keys = new_ckpt['state_dict'].keys()
+        for key in list(keys):
+            if 'expert' in keys:
+                new_ckpt['state_dict'].pop(key)
+
         torch.save(new_ckpt, os.path.join(args.target, f'{names[i]}.pth'))
 
 if __name__ == '__main__':
-    main()
+    main()