## What changes were proposed in this pull request?
I fixed a typo in the Scaladoc for the method `def struct(cols: Column*): Column`. 'retained' was misspelt as 'remained'.
## How was this patch tested?
Before:
Creates a new struct column.
If the input column is a column in a `DataFrame`, or a derived column expression
that is named (i.e. aliased), its name would be **remained** as the StructField's name,
otherwise, the newly generated StructField's name would be auto generated as
`col` with a suffix `index + 1`, i.e. col1, col2, col3, ...
After:
Creates a new struct column.
If the input column is a column in a `DataFrame`, or a derived column expression
that is named (i.e. aliased), its name would be **retained** as the StructField's name,
otherwise, the newly generated StructField's name would be auto generated as
`col` with a suffix `index + 1`, i.e. col1, col2, col3, ...
Author: sujithjay <sujith@logistimo.com>
Closes#18254 from sujithjay/fix-typo.
3a840048ed