more tweaks to make sure warnings are printed

Author: Shane Snyder

darshan-util/pydarshan/darshan/cli/summary.py

@@ -640,11 +640,11 @@ def build_sections(self):
         """
         self.sections = {}
         for fig in self.figures:
-            # skip empty figures
-            if fig.fig_html == None and fig.section_title != "I/O Summary":
-                # skip empty report sections, except for heatmap data in the
-                # "I/O Summary" section, as these plots contain an important
-                # warning message on how to generate heatmap plots
+            # skip empty figures that can be generated by report sections
+            # "Data Access by Category" and "Cross-Module Comparisons"
+            if (fig.fig_html == None and
+                (fig.section_title == "Data Access by Category" or
+                 fig.section_title == "Cross-Module Comparisons")):
                 continue
             # if a section title is not already in sections, add
             # the section title and a corresponding empty list