error messages for courses

app/views/admin/courses/partials/_form.html.erb

@@ -1,14 +1,6 @@
 <%= form_with(model: [:admin, course]) do |form| %>
   <% if course.errors.any? %>
-    <div id="error_explanation">
-      <h2><%= pluralize(course.errors.count, "error") %> prohibited this admin_course from being saved:</h2>
-
-      <ul>
-      <% course.errors.full_messages.each do |message| %>
-        <li><%= message %></li>
-      <% end %>
-      </ul>
-    </div>
+    <%= error_messages(course) %>
   <% end %>
   <div class="form-row">
     <div class="form-group col-md-6">