Bug 38117: Only show 'not checked in' message if item is checked out

Bug 38117: Only show 'not checked in' message if item is checked out

To test:
 1 - Enable system preference 'ShowAllCheckins'
 2 - Set system preference 'BlockReturnOfWithdrawnItems' to 'Block'
 3 - Check in an item
 4 - Note 'Item was not checked in message'
 5 - Confirm it happens for any item that is not currently issued
 6 - Check out an item to a patron
 7 - Mark the item as withdrawn
 8 - Check the item in
 9 - Note message 'Item was not checked in' appears too
10 - Apply patch
11 - Confirm checking in an item not checked out only shows 'Not checked out'
12 - Confirm the withdrawn item still shows 'Item was not checked in'
13 - Confirm above message remains whne checking in more items that were not issued

Signed-off-by: Michelle Spinney <mspinney@clamsnet.org>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>