Bug 36904: Fix batch->ill_batch

Bug 36904: Fix batch->ill_batch

This was missed when renaming follow-ups were added to bug 30719

1) Enable ILL, install FreeForm and checkout the current compatible branch with main
  bash <(curl -s https://raw.githubusercontent.com/ammopt/koha-ill-dev/master/start-ill-dev.sh)
  cd /kohadevbox/koha/Koha/Illbackends/FreeForm
  git checkout reorganize_ILL
2) Visit ILL module:
  http://localhost:8081/cgi-bin/koha/ill/ill-requests.pl
3) Type whatever search in the tiny 'Search' input box directly above the table
4) Notice you get an error. Apply patch. Repeat.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>