Fix up some more of the meta info container

lms/static/coffee/src/staff_grading/staff_grading.coffee

@@ -343,7 +343,7 @@ class StaffGrading
       meta_list.append("<li><span class='meta-info'>Pending:</span> #{@num_pending}</li>")
       meta_list.append("<li><span class='meta-info'>Graded:</span> #{@num_graded}</li>")
       meta_list.append("<li><span class='meta-info'>Needed for ML:</span> #{Math.max(@min_for_ml - @num_graded)}</li>")
-      @problem_meta_info.append(meta_list)
+      @problem_meta_info.html(meta_list)
 
       @prompt_container.html(@prompt)
       @prompt_name_container.html("#{@prompt_name}")

lms/static/sass/course/_staff_grading.scss

@@ -49,7 +49,7 @@ div.staff-grading {
         padding: 15px;
         margin-left: 0px;
     }
-    .ml-error-info-container,
+    .meta-info-wrapper
     {
         background-color: #eee;
         padding:15px;

lms/templates/instructor/staff_grading.html

@@ -18,7 +18,7 @@
 
 <div class="staff-grading" data-ajax_url="${ajax_url}">
 <div class="meta-info-wrapper">
-    <h3>Meta Information</h3>
+    <h3>Problem Information</h3>
     <div class="problem-meta-info-container">
     </div>
     <h3>Maching Learning Information</h3>