Possible to create a "hold cannot be placed" loop

[Andrea Neiman]

This emerged during Hopeless Holds testing (bug 1811710).

3.3+, and probably earlier though I haven't tested.

To reproduce:

* Pull up a record where all items are unholdable & your user has the ITEM_NOT_HOLDABLE.override permission at appropriate levels.
* Attempt to place a title-level hold, and you see the expected messages "Hold was not successfully placed.
Problem: The system could not find any items to match this hold request. You have permission to override some of the failed holds. Click Submit to override and place your hold on the selected items."
* Click SUBMIT.
* Screen refreshes and you see the same hold-failed messages; the hold is not placed.

Either the hold request override should not be permitted (and thus not display), or hold requests should always succeed here (and thus create potentially hopeless holds).