Fix error in esxi plugin

git-svn-id: https://svn.code.sf.net/p/xcat/code/xcat-core/trunk@15814 8638fb3e-16cb-4fca-ae20-7b5d299a9bcd

xCAT-server/lib/xcat/plugins/esx.pm

@@ -4225,7 +4225,7 @@ sub copycd {
     if ($::XCATSITEVALS{osimagerequired}){
           my $haveimages=xCAT::SvrUtils->update_tables_with_templates($distname, $arch,"","",checkonly=>1);
           unless ($haveimages) { 
-               $callback->({error => "No Templates found to support $distname($arch)"});
+               $output_handler->({error => "No Templates found to support $distname($arch)"});
           }
     }