pgsql: pgbench: Correct log level of message output when socket wait me

pgbench: Correct log level of message output when socket wait method fails.

The failure of socket wait method like "select()" doesn't terminate pgbench.
So the log level of error message when that failure happens should be ERROR.
But previously FATAL was used in that case.

Back-patch to v13 where pgbench started using common logging API.

Author: Yugo Nagata, Fabien COELHO
Reviewed-by: Kyotaro Horiguchi, Fujii Masao
Discussion: https://postgr.es/m/20210617005934.8bd37bf72efd5f1b38e6f482@sraoss.co.jp

Branch
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REL_13_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/3cc85d7d5353945bf5bdb26bb7771f40aeacaf0b

Modified Files
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src/bin/pgbench/pgbench.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)