Bug 8294: Fix display of serial enumeration for OPAC holds

It turns out that this was not a missing but a broken feature.
This patch corrects the template variables to make enumchron
show up on the item table for item level holds in the OPAC.

To test:
Try to place item level holds on
1) a record where at least one item
2) a record where none of the items
has items.enumchron information.

The column with enumchron should only show for 1), but not
for 2).

Signed-off-by: David Cook <dcook@prosentient.com.au>

Works as described.

Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>
(cherry picked from commit 815bcbc1d1)

Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>

koha-tmpl/opac-tmpl/prog/en/modules/opac-reserve.tt

@@ -433,7 +433,7 @@
                               <th>Last location</th>
                             [% END %]
                             <th>Call number</th>
-                            [% IF ( bibitemloo.itemdata_enumchron ) %]
+                            [% IF ( itemdata_enumchron ) %]
                               <th>Vol info</th>
                             [% END %]
                             <th>Information</th>
@@ -464,7 +464,7 @@
                                 <td class="holdingbranch">[% itemLoo.holdingBranchName %]</td>
                               [% END %]
                               <td class="call_no">[% itemLoo.callNumber %]</td>
-                              [% IF ( itemLoo.itemdata_enumchron ) %]<!-- test -->
+                              [% IF ( itemdata_enumchron ) %]
                                 <td class="vol_info">[% itemLoo.enumchron %]</td>
                               [% END %]
                               <td class="information">