pgsql: Fix comment in xlogutils.c

Fix comment in xlogutils.c

The existing callers of XLogReadDetermineTimeline() performing recovery
need to check a replay LSN position when determining on which timeline
to read a WAL page.  A portion of the comment describing this function
said exactly that, while referring to a routine for fetching a write
LSN, something not available in recovery.

Author: Kyotaro Horiguchi
Discussion: https://postgr.es/m/20200511.101619.2043820539323292957.horikyota.ntt@gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/078c9cd258e5ad8f54081c971b7b927f845e7505

Modified Files
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src/backend/access/transam/xlogutils.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)