Fix references to renamed function in comments
I renamed the function in commit
024c521117, but missed these
comments.
Reported-by: Richard Guo
Discussion: https://www.postgresql.org/message-id/CAMbWs4-jR6qc7JRMKwz-zXQy_AYLUZ3PHjGep4B91of321cqWw@mail.gmail.com