busybox

testsuite: typo in tr.tests

Hi

tr.tests script from bb 1.17 testsuite has wrong "optional"
conditional clauses. As result, some tr tests was skipped even if
CONFIG_FEATURE_TR_CLASSES=y. Patch attached fixes problem for me.

- Leonid

Signed-off-by: Leonid Lisovskiy <lly.dev@gmail.com>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>