Bug 35592: Fix closing tag in bookings alert

Bug 35592: Fix closing tag in bookings alert

To test:
1 - View a record details page for a record with items
2 - Click on the 'Items' tab
3 - Change 'Bookable' to 'Yes' and update for an item
4 - View the details page - place a booking
5 - Checkout the item to the patron it is booked for
6 - Note the alert shows, but encompasses the whole page
7 - Apply patch
8 - Check in the item
9 - Checkout the item again
10 - Note the alert shows above the checkouts page as expected

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>