Merge #10045: [trivial] Fix typos in comments

Summary:
dbf30ff [trivial] Fix typos in comments (practicalswift)

Tree-SHA512: a841c96ba1a80ab57206e8ef4fa9b40ecff2244075a5539fc09f57e763bf2e92b0ed089e32a0dbac3902518dcda43d224f75a3462a560148841746560640ba70

Backport of Core PR10045
https://github.com/bitcoin/bitcoin/pull/10045/

Test Plan: make check

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

Reviewed By: markblundeberg, O1 Bitcoin ABC, #bitcoin_abc

Differential Revision: https://reviews.bitcoinabc.org/D3022