Bug 8648: searchResults uses SQL query rather than GetMarcFromKohaField

Bug 8648: searchResults uses SQL query rather than GetMarcFromKohaField

Around line 1470-something:

    my $sth =
    $dbh->prepare(
            "SELECT tagfield FROM marc_subfield_structure WHERE kohafield LIKE
            'items.itemnumber'"
            );
    $sth->execute;

This patch replaces that with a call to GetMarcFromKohaField.

To test:
1) Apply patch.
2) Do a search that returns both available and unavailable items.
   You'll know if the patch isn't working.

Signed-off-by: Julian Maurice <julian.maurice@biblibre.com>
Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>