Bug 21036: Remove odd number of elements warnings from AuthoritiesMarc.pm

Like this one (16.11 line number):
Odd number of elements in anonymous hash at C4/AuthoritiesMarc.pm line 1070.

We need to add a scalar to some MARC::Field::subfield calls. In list context
an empty list returned affects the hash built around it.

Test plan:
Could reproduce this warning easily from OPAC authority search.
opac-authorities-home.pl calling BuildSummary.

Signed-off-by: Bouzid Fergani <bouzid.fergani@inlibro.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>

C4/AuthoritiesMarc.pm

@@ -994,14 +994,14 @@ sub BuildSummary {
             if ($type eq 'subfi') {
                 push @seefrom, {
                     heading => $field->as_string($marc21subfields),
-                    hemain  => $field->subfield( substr($marc21subfields, 0, 1) ),
+                    hemain  => scalar $field->subfield( substr($marc21subfields, 0, 1) ),
                     type    => ($field->subfield('i') || ''),
                     field   => $field->tag(),
                 };
             } else {
                 push @seefrom, {
                     heading => $field->as_string($marc21subfields),
-                    hemain  => $field->subfield( substr($marc21subfields, 0, 1) ),
+                    hemain  => scalar $field->subfield( substr($marc21subfields, 0, 1) ),
                     type    => $type,
                     field   => $field->tag(),
                 };
@@ -1017,8 +1017,8 @@ sub BuildSummary {
             if ($type eq 'subfi') {
                 push @seealso, {
                     heading => $field->as_string($marc21subfields),
-                    hemain  => $field->subfield( substr($marc21subfields, 0, 1) ),
-                    type    => $field->subfield('i'),
+                    hemain  => scalar $field->subfield( substr($marc21subfields, 0, 1) ),
+                    type    => scalar $field->subfield('i'),
                     field   => $field->tag(),
                     search  => $field->as_string($marc21subfields) || '',
                     authid  => $field->subfield('9') || ''
@@ -1026,7 +1026,7 @@ sub BuildSummary {
             } else {
                 push @seealso, {
                     heading => $field->as_string($marc21subfields),
-                    hemain  => $field->subfield( substr($marc21subfields, 0, 1) ),
+                    hemain  => scalar $field->subfield( substr($marc21subfields, 0, 1) ),
                     type    => $type,
                     field   => $field->tag(),
                     search  => $field->as_string($marc21subfields) || '',