pgsql: Fix recently introduced typos - Mailing list pgsql-committers

Fix recently introduced typos

This fixes typos in docs and comments introduced during the v18
development cycle, to keep them from ending up in backbranches.

Author: Jacob Brazeal <jacob.brazeal@gmail.com>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/CA+COZaCgGua25f2hSrjrDLJcJJAHkwoKgTTqUy-wyL1=64JNjw@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/847bbb21f8c4eb0e2b47417684ad2ba9255c9e80

Modified Files
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doc/src/sgml/indexam.sgml                   | 2 +-
src/backend/statistics/attribute_stats.c    | 2 +-
src/backend/storage/lmgr/lwlock.c           | 2 +-
src/backend/utils/activity/pgstat_backend.c | 2 +-
src/backend/utils/cache/inval.c             | 2 +-
src/tools/testwrap                          | 2 +-
6 files changed, 6 insertions(+), 6 deletions(-)