get-maintainer.pl: Dont fall over when L: contains a display name

Prior to this change e-mail addresses of the form "display name
<email>" would result into empty output. Also see
https://lists.xenproject.org/archives/html/xen-devel/2020-01/msg00753.html

Signed-off-by: Lars Kurth <lars.kurth@citrix.com>
Reviewed-by: Julien Grall <julien@xen.org>

scripts/get_maintainer.pl

@@ -1073,7 +1073,7 @@ sub add_categories {
 	    my $ptype = $1;
 	    my $pvalue = $2;
 	    if ($ptype eq "L") {
-		my $list_address = $pvalue;
+		my ($list_name, $list_address) = parse_email($pvalue);            
 		my $list_additional = "";
 		my $list_role = get_list_role($i);