pgsql: Fix typos in comments

Fix typos in comments

Author: Peter Smith <smithpb2250@gmail.com>
Discussion: /messages/by-id/CAHut+PsN_gmKu-KfeEb9NDARoTPbs4AN4PPu=6LZXFZRJ13SEw@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/8af57ad81578f825ac8c46840c841833db205106

Modified Files
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src/backend/access/transam/xlogreader.c | 2 +-
src/backend/commands/copyfrom.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)