Evaluate links for descriptor is broken

[ElectricMaxxx]

this:
https://github.com/symfony-cmf/sonata-phpcr-admin-integration-bundle/blob/master/src/Description/SonataEnhancer.php#L81
can not work. No idea why i fixed it that way, maybe cause the test doesn't match real admin names.
Something like:

$linkKey = substr($code, strlen($admin->getCode()) + 1);

looks more valid. So we should fix it and write more meaningfull tests for that case.