[EPLB][bugfix] Bugfix for fused mc2 (#6794)

### What this PR does / why we need it?
This pull request addresses a bug related to the fused mc2 functionality
within the EPLB (Expert Parallelism Load Balancing) system, specifically
impacting quantization and MoE communication.
### Does this PR introduce _any_ user-facing change?

### How was this patch tested?

- vLLM version: v0.15.0
- vLLM main:
83b47f67b1

Signed-off-by: Spicy-Stick <873805887@qq.com>
Signed-off-by: root <root@localhost.localdomain>

vllm_ascend/ops/fused_moe/moe_comm_method.py

@@ -70,7 +70,7 @@ class FusedExpertsResult:
     before_dispatch_evt: torch.npu.Event | None = None
     before_combine_evt: torch.npu.Event | None = None
     # For dynamic_eplb
-    group_list_type: int | None = None
+    group_list_type: int = 1
     expert_tokens: torch.Tensor | None = None
 
 
@@ -355,7 +355,6 @@ class FusedMC2CommImpl(MoECommMethod):
         if log2phy is not None:
             topk_ids = log2phy[topk_ids]
 
-        group_list_type = None
         expert_tokens = None
         if envs_ascend.VLLM_ASCEND_ENABLE_FUSED_MC2 == 1:
             out = torch.empty_like(hidden_states)
@@ -375,7 +374,6 @@ class FusedMC2CommImpl(MoECommMethod):
             expert_tokens = self.expert_token_nums
         elif envs_ascend.VLLM_ASCEND_ENABLE_FUSED_MC2 == 2:
             assert expert_map is not None, "expert_map cannot be None."
-            group_list_type = 1
             out, expert_tokens = torch.ops._C_ascend.dispatch_gmm_combine_decode(  # type: ignore
                 x=hidden_states,
                 expert_ids=topk_ids,
@@ -393,4 +391,4 @@ class FusedMC2CommImpl(MoECommMethod):
             )
         else:
             raise ValueError(f"Wrong value of {envs_ascend.VLLM_ASCEND_ENABLE_FUSED_MC2=}")
-        return FusedExpertsResult(routed_out=out, group_list_type=group_list_type, expert_tokens=expert_tokens)
+        return FusedExpertsResult(routed_out=out, expert_tokens=expert_tokens)