Since 5 scans for enroll was introduced it's not necessary to lower bz3_threshold anymore, there's a good probability that scan to verify matches with at least one enrolled sample.
Or rather, it never returns errors and aborts instead if memory cannot be allocated, so remove code that handled failures. https://bugs.freedesktop.org/show_bug.cgi?id=57869
https://bugs.freedesktop.org/show_bug.cgi?id=57426