[misc] fix: fix DataProto __getstate__ bug (#2962)

Author: vermouth1992

verl/protocol.py

@@ -332,9 +332,10 @@ def __getstate__(self):
 
         buffer = io.BytesIO()
         if version.parse(tensordict.__version__) >= version.parse("0.5.0") and self.batch is not None:
-            self.batch = self.batch.contiguous()
-            self.batch = self.batch.consolidate()
-        torch.save(self.batch, buffer)
+            batch_to_save = self.batch.contiguous().consolidate()
+        else:
+            batch_to_save = self.batch
+        torch.save(batch_to_save, buffer)
         buffer_bytes = buffer.getvalue()
         return buffer_bytes, self.non_tensor_batch, self.meta_info