xen: Avoid double free of virDomainDef in xenDaemonCreateXML

The virDomainDef is allocated by the caller and also used after
calling to xenDaemonCreateXML. So it must not get freed by the
callee.
Signed-off-by: NStefan Bader <stefan.bader@canonical.com>

src/xen/xend_internal.c

@@ -2171,7 +2171,6 @@ xenDaemonCreateXML(virConnectPtr conn, virDomainDefPtr def)
     if (xenDaemonDomainResume(conn, def) < 0)
         goto error;
 
-    virDomainDefFree(def);
     return 0;
 
   error: