pgsql: Fix typos in pgstat.c, reorderbuffer.c and pathnodes.h

Fix typos in pgstat.c, reorderbuffer.c and pathnodes.h

Reviewed-by: Thomas Munro <thomas.munro@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: /messages/by-id/50250765-5B87-4AD7-9770-7FCED42A6175@yesql.se

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/387925893edf2a3a30a8ddf2c6474d8a7eb056a5

Modified Files
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src/backend/postmaster/pgstat.c | 6 +++---
src/backend/replication/logical/reorderbuffer.c | 2 +-
src/include/nodes/pathnodes.h | 2 +-
3 files changed, 5 insertions(+), 5 deletions(-)