Add user badge autocompleter is not working correctly

Hi Shabana Blackborder,
I've found that the autocompleter on the user's badge page is not working correctly.
It doesn't respect text the user typed in the search field to find/add badge.

I've found that the field is using the entityreference field module's autocomplete callback.
That function needs the 'label' entity key defined in hook info to find target entities.

It was only a small change, but was hard to find.

I'll attach my patch.