pgbench: Use common logging API

Author: Fabien COELHO <[email protected]>
Reviewed-by: Michael Paquier <[email protected]>
Reviewed-by: Peter Eisentraut <[email protected]>
Discussion: https://www.postgresql.org/message-id/flat/alpine.DEB.2.21.1912241100390.3339@pseudo

Author: petere