fix session core when flt mgr init failed

src/sql/session/ob_sql_session_mgr.cpp

@@ -437,9 +437,14 @@ int ObSQLSessionMgr::create_session(const uint64_t tenant_id,
     } else if (mgr.is_valid_tenant_config()) {
       tmp_sess->set_flt_control_info(mgr.get_control_info());
     }
+
+    if (OB_FAIL(ret)) {
+      // do nothing
+    } else {
       tmp_sess->update_last_active_time();
       session_info = tmp_sess;
     }
+  }
   return ret;
 }