Rename field_parent into field_childs

partner.xml

@@ -273,7 +273,7 @@
     <record model="ir.ui.view" id="view_partner_category_tree">
       <field name="model">partner.category</field>
       <field name="type">tree</field>
-      <field name="field_parent">childs</field>
+      <field name="field_childs">childs</field>
       <field name="arch" type="xml">
         <![CDATA[
           <tree string="Partner Categories">