Fix return code tests.

tests/scripts/test002-populate

tests/scripts/test003-search

tests/scripts/test005-modrdn

tests/scripts/test006-acls

tests/scripts/test007-replication

tests/scripts/test009-referral

tests/scripts/test010-passwd

tests/scripts/test011-subtree-repl

tests/scripts/test012-glue

tests/scripts/test013-language

tests/scripts/test015-xsearch