pgsql: Improve error message for checksum failures in pgstat_database.c

Improve error message for checksum failures in pgstat_database.c

This log message was referring to conflicts, but it is about checksum
failures. The log message improved in this commit should never show up,
due to the fact that pgstat_prepare_report_checksum_failure() should
always be called before pgstat_report_checksum_failures_in_db(), with a
stats entry already created in the pgstats shared hash table. The three
code paths able to report database-level checksum failures follow
already this requirement.

Oversight in b96d3c389755.

Author: Wang Peng <215722532(at)qq(dot)com>
Discussion: https://postgr.es/m/tencent_9B6CD6D9D34AE28CDEADEC6188DB3BA1FE07@qq.com
Backpatch-through: 18

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/775fc014156bdfa6938ef02dce3d85364b1bd220

Modified Files
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src/backend/utils/activity/pgstat_database.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)