[RTADPA BW Tests] Fix the sprucing summary plot no longer appearing

Co-authored-by: lugrazet <luke.grazette@cern.ch>

python/MooreTests/make_bandwidth_test_page.py

@@ -124,7 +124,7 @@ def render_top_level_page(script_path: str,
         <p>
             Summary of bandwidth of all streams to disk (only available for those tests that run all sprucing stages):<br>
         </p>
-        <object type="image/png" data="{fname_helper.to_disk_bar_chart_path(full_path=False)}"></object>
+        <object type="image/png" data="{FileNameHelper(process="spruce", stream_config="").to_disk_bar_chart_path(full_path=False)}"></object>
         """
 
     html_str += """