**Describe what's wrong**

Query with rollup using same selected field name as the name of underlying column reports structure mismatch

**Does it reproduce on recent release?**

yes

**How to reproduce**

`21.9.2.17`

```sql
CREATE TABLE test
(
    `d` DateTime,
    `a` LowCardinality(String),
    `b` UInt64
)
ENGINE = MergeTree
PARTITION BY toDate(d)
ORDER BY d;

SELECT *
FROM (
    SELECT
        a,
        max((d, b)).2 AS value
    FROM test
    GROUP BY rollup(a)
)
WHERE a <> '';
```

**Expected behavior**

This used to return an ok result on v21.8

**Error message and/or stacktrace**

> Code: 352. DB::Exception: Block structure mismatch in (columns with identical name must have identical structure) stream: different columns:
> notEquals(a, '') LowCardinality(UInt8) ColumnLowCardinality(size = 0, UInt8(size = 0), ColumnUnique(size = 1, UInt8(size = 1)))
> notEquals(a, '') LowCardinality(UInt8) Const(size = 0, ColumnLowCardinality(size = 1, UInt8(size = 1), ColumnUnique(size = 2, UInt8(size = 2)))). (AMBIGUOUS_COLUMN_NAME) (version 21.9.2.17 (official build))



{
            auto row_level_security_step = std::make_unique<FilterStep>(
                query_plan.getCurrentDataStream(),
                expressions.filter_info->actions,
                expressions.filter_info->column_name,
                expressions.filter_info->do_remove_column);
            row_level_security_step->setStepDescription("Row-level security filter");
            query_plan.addStep(std::move(row_level_security_step));
        }
        if (expressions.prewhere_info)
        {
            if (expressions.prewhere_info->row_level_filter)
            {
                auto row_level_filter_step = std::make_unique<FilterStep>(
                    query_plan.getCurrentDataStream(),
                    expressions.prewhere_info->row_level_filter,
                    expressions.prewhere_info->row_level_column_name,
                    false);
                row_level_filter_step->setStepDescription("Row-level security filter (PREWHERE)");
                query_plan.addStep(std::move(row_level_filter_step));
            }
            auto prewhere_step = std::make_unique<FilterStep>(
                query_plan.getCurrentDataStream(),
                expressions.prewhere_info->prewhere_actions,
                expressions.prewhere_info->prewhere_column_name,
                expressions.prewhere_info->remove_prewhere_column);
            prewhere_step->setStepDescription("PREWHERE");
            query_plan.addStep(std::move(prewhere_step));
        }
    }