pgsql: pgbench has #defines for number of branches, tellers, and

Log Message:
-----------
pgbench has #defines for number of branches, tellers, and accounts. There
are used to populate the tables with -i, but when running actual benchmark
it has values separately hard-coded in the query metacommands. This patch
makes the metacommands obtain their values from the relevant #defines.

Patch provided by Jeff Janes.

Modified Files:
--------------
pgsql/contrib/pgbench:
pgbench.c (r1.90 -> r1.91)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/contrib/pgbench/pgbench.c?r1=1.90&r2=1.91)