Bug 11349: (qa follow-up) Fix pod

Bug 11349: (qa follow-up) Fix pod

 FAIL   cataloguing/value_builder/unimarc_field_125.pl
   FAIL   pod
    *** ERROR: empty =head1  in file cataloguing/value_builder/unimarc_field_125.pl
    *** ERROR: Spurious text after =cut  in file cataloguing/value_builder/unimarc_field_125.pl

 FAIL   cataloguing/value_builder/unimarc_field_126b.pl
   FAIL   pod
    *** ERROR: empty =head1  in file cataloguing/value_builder/unimarc_field_126b.pl
    *** ERROR: Spurious text after =cut  in file cataloguing/value_builder/unimarc_field_126b.pl

 FAIL   cataloguing/value_builder/unimarc_field_225a.pl
   FAIL   pod
    *** ERROR: =over on line 40 without closing =back (at head1)  in file cataloguing/value_builder/unimarc_field_225a.pl
    *** ERROR: empty =head1  in file cataloguing/value_builder/unimarc_field_225a.pl

Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>