[Bugfix][V1][P/D]Fix the issue of occasional garbled output for P2pNcclConnector (#20263)

Signed-off-by: Abatom <abzhonghua@gmail.com>

vllm/distributed/kv_transfer/kv_connector/v1/p2p/p2p_nccl_engine.py

@@ -310,6 +310,7 @@ class P2pNcclEngine:
                 elif data["cmd"] == "PUT":
                     tensor_id = data["tensor_id"]
                     try:
+                        with torch.cuda.stream(self.recv_stream):
                             tensor = torch.empty(data["shape"],
                                                  dtype=getattr(
                                                      torch, data["dtype"]),