[Bugfix] bugfix for moe_mlp (#4822)

### What this PR does / why we need it?
This PR fixes a bug in the moe_mlp module by correcting the arguments
passed to the torch_npu.npu_dequant_swiglu_quant function.It properly
converts group_list from a cumulative sum to counts for the group_index
parameter.

### Does this PR introduce _any_ user-facing change?
No


- vLLM version: v0.12.0
- vLLM main:
ad32e3e19c

---------

Signed-off-by: tanqingshan (A)  <50050625@china.huawei.com>
Co-authored-by: tanqingshan (A) <50050625@china.huawei.com>

tests/ut/ops/test_fused_moe.py

@@ -294,13 +294,13 @@ class TestCumsumGroupList(TestBase):
     def test_cumsum_group_list_with_type_0(self):
         group_list = self.experts.cumsum(dim=0)
         group_list_type = 0
-        result = cumsum_group_list(group_list, group_list_type)
+        result = cumsum_group_list(group_list, group_list_type, 0)
         self.assertTrue(torch.equal(result, self.group_list))
 
     def test_cumsum_group_list_with_type_1(self):
         group_list = self.experts
         group_list_type = 1
-        result = cumsum_group_list(group_list, group_list_type)
+        result = cumsum_group_list(group_list, group_list_type, 0)
         self.assertTrue(torch.equal(result, self.group_list))
 
     def test_cumsum_group_list_with_type_2(self):
@@ -313,6 +313,7 @@ class TestCumsumGroupList(TestBase):
         group_list_type = 2
         result = cumsum_group_list(group_list,
                                    group_list_type,
+                                   0,
                                    active_num=self.active_num,
                                    expert_num=self.expert_num)
         self.assertTrue(torch.equal(result, self.group_list))
@@ -592,4 +593,4 @@ class TestUnifiedApplyMLP(TestBase):
 
         self.assertTrue(mock_forward_context.with_quant)
         self.assertEqual(result.shape, hidden_states_shape)
-        self.assertEqual(result.dtype, torch.bfloat16)
+        self.assertEqual(result.dtype, torch.bfloat16)