Bug 3704: SIP Checkin of not checked out item returns error without reason

Bug 3704: SIP Checkin of not checked out item returns error without reason

Checking in an available item returns an error (which is correct) without
giving a reason for the failure as screen_msg (aka AF field in SIP2 is empty).

Based on code suggested by Patrick Langer <patrick.langer@easycheck.org>

Signed-off-by: Ulrich Kleiber <ulrich.kleiber@bsz-bw.de>
Signed-off-by: Ian Walls <ian.walls@bywatersolutions.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
(cherry picked from commit a2ee6443b9643ad0780ad62ef63d0a06d5c674f0)

Signed-off-by: Chris Nighswonger <chris.nighswonger@gmail.com>