Bug 14710: Make the export checkout list export only the checked out item infos

Bug 14710: Make the export checkout list export only the checked out item infos

This has been introduced by bug 11703.

Bug 13190 should have been fixed it.

If the pref ExportWithCsvProfile is defined with a MARC CSV profile and
it contains item infos to display, only info from the checked out item
should be displayed.

Test plan:
0/ Don't apply this patch
1/ Create a biblio with 1+ items
2/ Check one of the item out to a patron
3/ Define a CSV profile which contains item fields ("245$a|952$p" for instance)
4/ Export the item (from circ/circulation/pl) using the CSV option
Note that the csv contains the barcode from all items
5/ Apply this patch and repeat 4.
6/ Note that the csv contains only the barcode from the checked out
item.

Signed-off-by: Hector Castro <hector.hecaxmmx@gmail.com>
Works as advertised

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>