Merge #11417: Correct typo in comments

Summary:
6f33d8c Correct typo in comments (Johnson Lau)

Pull request description:

I think this is a search and replace mistake

Tree-SHA512: a83e081b817f1607496bfdcee47593d45d75cbe72effe944cdb5494b49a341eeeebdeb954f6db59dfa1ddfa350a117a4b26c754725a3459be78f2a1a093c6fde

Backport of Core PR11417
https://github.com/bitcoin/bitcoin/pull/11417

Test Plan:

make check

Reviewers: deadalnix, Fabien, jasonbcox, O1 Bitcoin ABC, #bitcoin_abc

Reviewed By: jasonbcox, O1 Bitcoin ABC, #bitcoin_abc

Differential Revision: https://reviews.bitcoinabc.org/D3876