pgsql: track_io_timing logging: Don't special case 0 ms.

track_io_timing logging: Don't special case 0 ms.

Adjust track_io_timing related logging code added by commit 94d13d474d.
Make it consistent with other nearby autovacuum and autoanalyze logging
code by removing logic that suppressed zero millisecond outputs.

log_autovacuum_min_duration log output now reliably shows "read:" and
"write:" millisecond-based values in its report (when track_io_timing is
enabled).

Author: Peter Geoghegan <pg(at)bowt(dot)ie>
Reviewed-By: Stephen Frost <sfrost(at)snowman(dot)net>
Discussion: https://postgr.es/m/CAH2-WznW0FNxSVQMSRazAMYNfZ6DR_gr5WE78hc6E1CBkkJpzw@mail.gmail.com
Backpatch: 14-, where the track_io_timing logging was introduced.

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/bda822554b96c6564911df95fcb898d6c30efe46

Modified Files
--------------
src/backend/access/heap/vacuumlazy.c | 15 +++++----------
src/backend/commands/analyze.c | 15 +++++----------
2 files changed, 10 insertions(+), 20 deletions(-)