Use render_pdf for the substitutions print view, too

aleksis/apps/chronos/views.py

@@ -360,9 +360,8 @@ def substitutions(
             wanted_day, "substitutions_by_date"
         )
 
-        template_name = "chronos/substitutions.html"
+        return render(request, "chronos/substitutions.html", context)
     else:
         context["days"] = day_contexts
-        template_name = "chronos/substitutions_print.html"
 
-    return render(request, template_name, context)
+        return render_pdf(request, "chronos/substitutions_print.html", context)