bat_event_field_widget_form_alter does not check field it is altering

Problem/Motivation

I had a taxonomy reference field on my bat_event entity. When adding an event, not all terms were shown in the select field. After some debugging I noticed bat_event_field_widget_form_alter() was the culprit.

Proposed resolution

Fix the hook implementation to check the field it is altering.

Remaining tasks

Write patch

User interface changes

N/A

API changes

Data model changes

Release notes snippet