Thread: pgsql: Fix outdated bit in README.tuplock

Fix outdated bit in README.tuplock

Apparently this information has been outdated since first committed,
because we adopted a different implementation during development per
reviews and this detail was not updated in the README.

This has been wrong since commit 0ac5ad5134f2 introduced the file in
2013.  Backpatch to all live branches.

Reported-by: Will Mortensen <will@extrahop.com>
Discussion: https://postgr.es/m/CAMpnoC6yEQ=c0Rdq-J7uRedrP7Zo9UMp6VZyP23QMT68n06cvA@mail.gmail.com

Branch
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REL_13_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/acf94a0d3661c4c29a7e845ef01ae143419a2c58

Modified Files
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src/backend/access/heap/README.tuplock | 9 ++-------
1 file changed, 2 insertions(+), 7 deletions(-)