fix conditional block (#32243)

paddle/fluid/operators/controlflow/conditional_block_op.h

@@ -79,8 +79,7 @@ class ConditionalOp : public framework::OperatorBase {
       platform::DeviceContextPool::Instance().Get(ips[0]->place())->Wait();
       res = cpu_tensor.data<bool>()[0];
 #endif
-    }
-    if (platform::is_npu_place(ips[0]->place())) {
+    } else if (platform::is_npu_place(ips[0]->place())) {
 #ifdef PADDLE_WITH_ASCEND_CL
       framework::LoDTensor cpu_tensor;
       framework::TensorCopy(*ips[0], platform::CPUPlace(), &cpu_tensor);