Bug 38128: (Bug 35329 follow-up) Filter ERM users to users with erm permission

Bug 38128: (Bug 35329 follow-up) Filter ERM users to users with erm permission

There was a silly mistake, we passed the TT var erm_users instead of the
string "erm_users".
It should also be passed to patron_search_modal to display the note.

Test plan:
Confirm that with this patch a patron search in the ERM module returns
only patrons with the erm permission.

Signed-off-by: Pedro Amorim <pedro.amorim@ptfs-europe.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>