pgsql: pgstat: consistent function comment formatting.

pgstat: consistent function comment formatting.

There was a wild mishmash of function comment formatting in pgstat, making it
hard to know what to use for any new function and hard to extend existing
comments (particularly due to randomly different forms of indentation).

Author: Andres Freund <andres(at)anarazel(dot)de>
Reviewed-By: Thomas Munro <thomas(dot)munro(at)gmail(dot)com>
Discussion: https://postgr.es/m/20220329191727.mzzwbl7udhpq7pmf@alap3.anarazel.de
Discussion: https://postgr.es/m/20220308205351.2xcn6k4x5yivcxyd@alap3.anarazel.de

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/edadf8098f4b2ca50bcc449f8857d0cc960b3c90

Modified Files
--------------
src/backend/postmaster/pgstat.c | 636 ++++++++---------------
src/backend/utils/activity/pgstat_archiver.c | 9 +-
src/backend/utils/activity/pgstat_bgwriter.c | 7 +-
src/backend/utils/activity/pgstat_checkpointer.c | 7 +-
src/backend/utils/activity/pgstat_database.c | 75 +--
src/backend/utils/activity/pgstat_function.c | 3 +-
src/backend/utils/activity/pgstat_relation.c | 77 ++-
src/backend/utils/activity/pgstat_replslot.c | 34 +-
src/backend/utils/activity/pgstat_slru.c | 26 +-
src/backend/utils/activity/pgstat_subscription.c | 27 +-
src/backend/utils/activity/pgstat_wal.c | 7 +-
11 files changed, 300 insertions(+), 608 deletions(-)