[Bugfix] Fix torch.compile error for DP + MoE on CPU Backend (#31650)

Signed-off-by: kunzh <zhikun.wu@outlook.com>

vllm/model_executor/layers/fused_moe/layer.py

@@ -1899,11 +1899,11 @@ class FusedMoE(CustomOp):
                 )
 
                 post_quant_allgather = (
-                    has_flashinfer_trtllm_fused_moe()
-                    and self.quant_method is not None
+                    self.quant_method is not None
                     and self.dp_size > 1
                     and self.use_ep
                     and isinstance(self.quant_method, ModelOptNvFp4FusedMoE)
+                    and has_flashinfer_trtllm_fused_moe()
                 )
                 if post_quant_allgather:
                     hidden_states_to_dispatch, extra_tensors = (