pgsql: C comments: "a" <--> "an" corrections

C comments:  "a" <--> "an" corrections

Reported-by: Michael Paquier, Abhijit Menon-Sen

Discussion: https://postgr.es/m/20180305045854.GB2266@paquier.xyz

Author: Michael Paquier, Abhijit Menon-Sen, me

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/20b4323bd107920a3c3e60452442e8e2cee302d2

Modified Files
--------------
config/c-library.m4                          | 2 +-
src/backend/access/gin/ginvacuum.c           | 2 +-
src/backend/catalog/aclchk.c                 | 2 +-
src/backend/commands/cluster.c               | 2 +-
src/backend/executor/instrument.c            | 2 +-
src/backend/libpq/pqformat.c                 | 2 +-
src/backend/nodes/readfuncs.c                | 2 +-
src/backend/utils/adt/nabstime.c             | 2 +-
src/backend/utils/cache/relcache.c           | 2 +-
src/bin/pgbench/t/001_pgbench_with_server.pl | 2 +-
10 files changed, 10 insertions(+), 10 deletions(-)