-Fix problem where Xen operations could fail to update the vm table

git-svn-id: https://svn.code.sf.net/p/xcat/code/xcat-core/trunk@2492 8638fb3e-16cb-4fca-ae20-7b5d299a9bcd

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

@@ -768,6 +768,7 @@ sub dohyp {
   my @exargs=@{$namedargs{-args}};
   my $node;
   my $args = \@exargs;
+  $vmtab = xCAT::Table->new("vm");
 
 
   $hypconn= Sys::Virt->new(uri=>"xen+ssh://".$hyp);