web/web_easy_switch_company/view/res_users_view.xml

<?xml version="1.0" encoding="UTF-8"?>
<openerp>
    <data>

        <record id="view_res_users_simple_modif_form" model="ir.ui.view">
            <field name="name">res.users.form</field>
            <field name="model">res.users</field>
            <field name="inherit_id" ref="base.view_users_form_simple_modif"/>
            <field name="arch" type="xml">
                <!-- hide old behaviour to change company -->
                <field name="company_id" position="replace" />
            </field>
        </record>
    </data>
</openerp>