Fix a bug when query bitmap return wrong result, even the simplest query.
Such as
```
CREATE TABLE `pv_bitmap_fix2` (
`dt` int(11) NULL COMMENT "",
`page` varchar(10) NULL COMMENT "",
`user_id_bitmap` bitmap BITMAP_UNION NULL COMMENT ""
) ENGINE=OLAP
AGGREGATE KEY(`dt`, `page`)
COMMENT "OLAP" DISTRIBUTED BY HASH(`dt`) BUCKETS 2
PROPERTIES (
"replication_allocation" = "tag.location.default: 1",
"in_memory" = "false",
"storage_format" = "V2"
)
Insert any hundreds of rows of data
select count(distinct user_id_bitmap) from pv_bitmap_fix2
the result is wrong
```
This is a bug of vectorization of storage layer.
b8e6c3a00c