BUG #3503: Benchmark scripts broken

The following bug has been logged online:

Bug reference:      3503
Logged by:          Justin Hibbits
Email address:      justin.hibbits@baesystems.com
PostgreSQL version: 8.2.4
Operating system:   Linux
Description:        Benchmark scripts broken
Details:

It appears that the benchmark script src/test/bench/create.sh is broken, in
that it tries to execute "postgres -D${1} postgres", which is invalid
according to postgres.