pgsql: Fix up some misusage of appendStringInfo() and friends

Fix up some misusage of appendStringInfo() and friends

Change to appendStringInfoChar() or appendStringInfoString() where those
can be used.

Author: David Rowley <david(dot)rowley(at)2ndquadrant(dot)com>
Reviewed-by: Ashutosh Bapat <ashutosh(dot)bapat(at)enterprisedb(dot)com>

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/77d05706beb115b412728bd94dce16d83795583d

Modified Files
--------------
contrib/postgres_fdw/deparse.c | 32 +++++++++++-----------
src/backend/commands/subscriptioncmds.c | 10 +++----
src/backend/nodes/outfuncs.c | 6 ++--
.../libpqwalreceiver/libpqwalreceiver.c | 12 ++++----
src/backend/utils/adt/ruleutils.c | 20 +++++++-------
src/backend/utils/adt/xml.c | 4 +--
src/backend/utils/mmgr/freepage.c | 8 +++---
src/bin/pg_dump/pg_dump.c | 5 ++--
src/bin/pg_dump/pg_dumpall.c | 2 +-
src/bin/psql/command.c | 4 +--
src/bin/psql/describe.c | 2 +-
src/bin/scripts/createuser.c | 2 +-
src/interfaces/libpq/fe-connect.c | 4 +--
13 files changed, 55 insertions(+), 56 deletions(-)