Error out on too many command-line arguments

Fix up oid2name, pg_upgrade, and pgbench to error out on too many
command-line arguments.  This makes it match the behavior of other
PostgreSQL programs.

Author: Peter Eisentraut, Ibrar Ahmed
Discussion: https://www.postgresql.org/message-id/flat/f2554627-04e7-383a-ef01-ab99bb6a291c%402ndquadrant.com