Bug 33603: Fix misc/maintenance/search_for_data_inconsistencies.pl when biblio.biblio...

Bug 33603: Fix misc/maintenance/search_for_data_inconsistencies.pl when biblio.biblionumber on control field

Since bug 29486, misc/maintenance/search_for_data_inconsistencies.pl search for biblio.biblionumber in MARC record with $record->subfield().
This fails when field is a control field (< 10).
Idem for biblioitems.biblioitemnumber

Test plan :
1.0) On a UNIMARC database (biblio.biblionumber is on 001)
1.1) Run misc/maintenance/search_for_data_inconsistencies.pl
=> Without patch you get error : Control fields (generally, just tags below 010) do not have subfields, use data()
=> With patch no error
2.0) On a MARC21 database (biblio.biblionumber is on 999c)
2.1) Run misc/maintenance/search_for_data_inconsistencies.pl
=> Check you see no error

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>