pgsql: Fix misc typos in comments.

Fix misc typos in comments.

Spotted mostly by Fabien Coelho.

Discussion: https://www.postgresql.org/message-id/alpine.DEB.2.21.1901230947050.16643@lancre

Branch
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REL_11_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/0359d832128485840bd7dcf0b09646ad752f6a72

Modified Files
--------------
contrib/pgcrypto/pgp-decrypt.c      | 2 +-
src/backend/access/gin/ginget.c     | 2 +-
src/backend/executor/execParallel.c | 2 +-
src/backend/parser/gram.y           | 2 +-
src/backend/utils/cache/typcache.c  | 2 +-
src/bin/pgbench/pgbench.c           | 4 ++--
src/include/nodes/execnodes.h       | 2 +-
src/include/port.h                  | 2 +-
src/pl/plpython/plpy_elog.c         | 2 +-
9 files changed, 10 insertions(+), 10 deletions(-)