pgsql: doc: double-quote use of %f, %p, and %r in literal commands.

doc: double-quote use of %f, %p, and %r in literal commands.

Path expansion might expose characters like spaces which would cause
command failure, so double-quote the examples. While %f doesn't need
quoting since it uses a fixed character set, it is best to be
consistent.

Discussion: https://postgr.es/m/aROPCQCfvKp9Htk4@momjian.us

Backpatch-through: master

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/43e6929bb2945553df021874914ade88743abc1f

Modified Files
--------------
doc/src/sgml/backup.sgml | 8 ++++----
doc/src/sgml/config.sgml | 4 ++--
doc/src/sgml/high-availability.sgml | 4 ++--
doc/src/sgml/ref/pgarchivecleanup.sgml | 4 ++--
src/backend/utils/misc/postgresql.conf.sample | 4 ++--
5 files changed, 12 insertions(+), 12 deletions(-)