[C++] Resolve follow-up reviews for TopK/BottomK

[asfimport]

There are some follow-up reviews for topK/bottomK kernel (ARROW-1565) that were requested after PR was closed. This issue is to resolve them.

Reporter: Eduardo Ponce / @edponce
Assignee: Alexander Ocsa / @aocsa

Related issues:

• [C++][Compute] Implement TopK/BottomK (is a child of)

PRs and other links:

• GitHub Pull Request #11132

_{Note: This issue was originally created as ARROW-13974. Please see the migration documentation for further details.}

[asfimport]

David Li / @lidavidm:
Issue resolved by pull request 11132
#11132