pgsql: Fix invalid function references in a few comments

Fix invalid function references in a few comments These appear to have been forgotten when the functions were renamed in 1fd687a03. Backpatch-through: 13, where the functions were renamed Branch -- REL_13_STABLE Details --- https://git.postgresql.org/pg/commitdiff/4d655f154565662cbd11f1

pgsql: Fix invalid function references in a few comments

Fix invalid function references in a few comments These appear to have been forgotten when the functions were renamed in 1fd687a03. Backpatch-through: 13, where the functions were renamed Branch -- master Details --- https://git.postgresql.org/pg/commitdiff/b27c90bbe4a3d607f8fc6703c7183