[Bugfix] Fix AttributeError: 'Stream' object has no attribute 'dp_size'

[jeejeelee]

Purpose

#31533 deleted the shared_experts_stream attribute in FusedMoEModularKernel, which led to LoRA MoE initialization failure.

(EngineCore_DP0 pid=1301291)   File "/vllm/vllm/model_executor/layers/fused_moe/modular_kernel.py", line 698, in __init__
(EngineCore_DP0 pid=1301291)     and moe_parallel_config.dp_size > 1
(EngineCore_DP0 pid=1301291)         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
(EngineCore_DP0 pid=1301291) AttributeError: 'Stream' object has no attribute 'dp_size'

Test Plan

Test Result

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[gemini-code-assist]

Code Review

The pull request removes the shared_experts_stream argument from a function call within the _inject_lora_into_fused_moe method in vllm/lora/layers/fused_moe.py.