[Misc] Fix Qwen2-MoE shared_expert_gate (#31339)

Signed-off-by: Jee Jee Li <pandaleefree@gmail.com>

vllm/model_executor/models/qwen2_moe.py

@@ -111,7 +111,7 @@ class Qwen2MoeMLP(nn.Module):
         out, _ = self.down_proj(out)
 
         if self.expert_gate is not None:
-            out = F.sigmoid(self.expert_gate(x)) * out
+            out = F.sigmoid(self.expert_gate(x)[0]) * out
 
         return out
 
@@ -140,7 +140,13 @@ class Qwen2MoeSparseMoeBlock(nn.Module):
             prefix=f"{prefix}.gate",
         )
 
-        self.shared_expert_gate = torch.nn.Linear(config.hidden_size, 1, bias=False)
+        self.shared_expert_gate = ReplicatedLinear(
+            config.hidden_size,
+            1,
+            bias=False,
+            quant_config=None,
+            prefix=f"{prefix}.shared_expert_gate",
+        )
 
         if config.shared_expert_intermediate_size > 0:
             self.shared_expert = Qwen2MoeMLP(