fix int8 (#35504)

paddle/fluid/framework/ir/multihead_matmul_fuse_pass.cc

@@ -903,8 +903,6 @@ int MultiHeadMatmulV2FusePass::BuildFusionV2(Graph* graph,
             float, softmax_qk_op_desc->GetAttr("out_threshold"));
         multihead_op_desc.SetAttr("dp_probs", qkv_plugin_scale);
       }
-    } else {
-      multihead_op_desc.SetAttr("qkv2context_plugin_int8", false);
     }
 
     auto* multihead = graph->CreateOpNode(&multihead_op_desc);

paddle/fluid/inference/tensorrt/convert/multihead_matmul_op.cc

@@ -42,8 +42,7 @@ class MultiheadMatMulOpConverter : public OpConverter {
 
     float* weight_data = nullptr;
     bool enable_int8 = op_desc.HasAttr("enable_int8");
-    bool qkv2context_plugin_int8 =
-        BOOST_GET_CONST(bool, op_desc.GetAttr("qkv2context_plugin_int8"));
+    bool qkv2context_plugin_int8 = op_desc.HasAttr("qkv2context_plugin_int8");
     float in_scale = 0.;
 
     if (enable_int8) {