## What changes were proposed in this pull request?
Prior this pr, the following code would cause an NPE:
`case class point(a:String, b:String, c:String, d: Int)`
`val data = Seq(
point("1","2","3", 1),
point("4","5","6", 1),
point("7","8","9", 1)
)`
`sc.parallelize(data).toDF().registerTempTable("table")`
`spark.sql("select a, b, c, count(d) from table group by a, b, c GROUPING SETS ((a)) ").show()`
The reason is that when the grouping_id() behavior was changed in #10677, some code (which should be changed) was left out.
Take the above code for example, prior #10677, the bit mask for set "(a)" was `001`, while after #10677 the bit mask was changed to `011`. However, the `nonNullBitmask` was not changed accordingly.
This pr will fix this problem.
## How was this patch tested?
add integration tests
Author: wangyang <wangyang@haizhi.com>
Closes#15416 from yangw1234/groupingid.
fb0d60814a