Bug 17088 - Bad MARC XML can halt export_records.pl

Bug 17088 - Bad MARC XML can halt export_records.pl

If export_records.pl encounters a record that fails to load correctly as
a MARC::Record the export process will fail and only the records
encountered up to that point will be exported.

Test Plan:
1) Pick a record in your database, and replace the biblioitems.marcxml field with some random characters
2) Export your records using the command:
   misc/export_records.pl  --format xml --record-type bibs --filename /tmp/biblios.xml
3) Note you get an error and the script ends prematurely
4) Apply this patch
5) Repeat step 2
6) Note the full record set is exported ( except for your bad record )
7) Note an error is still generated for your bad record ( useful for
    tracking down bad records ).

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Brendan Gallagher <brendan@bywatersolutions.com>
(cherry picked from commit e72a8ab260abed11b02266d77bc17d831884ed40)
Signed-off-by: Frédéric Demians <f.demians@tamil.fr>