traverser: emit starttime/expiration keys for update

Problem: While update() for match-allocate operations
emit starttime/expiration keys to comply with RV1,
update() for update-<allocate|reserve> operations
doesn't.

Modify the second update() method to comply with RV1
as well.

resource/traversers/dfu_impl_update.cpp

@@ -531,7 +531,17 @@ int dfu_impl_t::update (vtx_t root, std::shared_ptr<match_writers_t> &writers,
     needs = static_cast<unsigned int>(m_graph_db->metadata
                                           .v_rt_edges[dom].get_needs ());
     m_color.reset ();
-    return (upd_dfv (root, writers, needs, x, jobmeta, false, dfu) > 0)? 0: -1;
+
+    if ( (rc = upd_dfv (root, writers, needs, x, jobmeta, false, dfu)) > 0) {
+         uint64_t starttime = jobmeta.at;
+         uint64_t endtime = jobmeta.at + jobmeta.duration;
+         if (writers->emit_tm (starttime, endtime) == -1) {
+             m_err_msg += __FUNCTION__;
+             m_err_msg += ": emit_tm returned -1.\n";
+         }
+    }
+
+    return (rc > 0)? 0: -1;
 }
 
 int dfu_impl_t::remove (vtx_t root, int64_t jobid)