pgsql: Make blkreftable API use size_t/ssize_t consistently

Make blkreftable API use size_t/ssize_t consistently

It was using int for the input and output length, where size_t or
ssize_t would be more appropriate. It might not matter in practice,
but it makes the APIs consistent at all levels.

Reviewed-by: Heikki Linnakangas <hlinnaka(at)iki(dot)fi>
Discussion: https://www.postgresql.org/message-id/flat/f9aab072-0078-49e4-ab93-3b08086a4406(at)eisentraut(dot)org

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/7b87f08e8778c2d38c95e3808419e2d18c55c672

Modified Files
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src/backend/backup/walsummary.c | 14 +++++++-------
src/bin/pg_walsummary/pg_walsummary.c | 10 +++++-----
src/common/blkreftable.c | 16 ++++++++--------
src/include/backup/walsummary.h | 4 ++--
src/include/common/blkreftable.h | 2 +-
5 files changed, 23 insertions(+), 23 deletions(-)