Bug 32798: Update parameter passed to Koha::Biblio::Metadata->record

Bug 32798: Update parameter passed to Koha::Biblio::Metadata->record

To test:
1 - Enable OAI sets, and define a set with mapping 952 y = BK
2 - perl misc/migration_tools/build_oai_sets.pl -v -i -r
3 - The script dies:
    Koha::Biblio::Metadata->record must be called on an instantiated object or like a class method with a record passed in parameter
4 - Apply patch
5 - Repeat
6 - Success!

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Edit: tcohen updated indentation