pgsql: Use the terminology "WAL file" not "log file" more consistently.

Use the terminology "WAL file" not "log file" more consistently.

Referring to the WAL as just "log" invites confusion with the
postmaster log, so avoid doing that in docs and error messages.
Also shorten "WAL segment file" to just "WAL file" in various
places.

Bharath Rupireddy, reviewed by Nathan Bossart and Kyotaro Horiguchi

Discussion: https://postgr.es/m/CALj2ACUeXa8tDPaiTLexBDMZ7hgvaN+RTb957-cn5qwv9zf-MQ@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/31dcfae83c001c6cdfd1e67c11adb9149f564da0

Modified Files
--------------
doc/src/sgml/backup.sgml | 14 +++----
doc/src/sgml/config.sgml | 4 +-
doc/src/sgml/protocol.sgml | 2 +-
doc/src/sgml/ref/pg_basebackup.sgml | 2 +-
doc/src/sgml/ref/pg_waldump.sgml | 10 ++---
doc/src/sgml/wal.sgml | 60 +++++++++++++--------------
src/backend/access/transam/xlogreader.c | 10 ++---
src/backend/access/transam/xlogrecovery.c | 6 +--
src/backend/access/transam/xlogutils.c | 4 +-
src/backend/replication/walreceiver.c | 6 +--
src/backend/utils/misc/postgresql.conf.sample | 8 ++--
src/bin/pg_resetwal/pg_resetwal.c | 2 +-
src/bin/pg_upgrade/controldata.c | 2 +-
src/bin/pg_waldump/pg_waldump.c | 4 +-
14 files changed, 67 insertions(+), 67 deletions(-)