[FIX] product: Field display_name in product template form view

Steps to reproduce the bug:
- Go to Sales app and open the form view of a product P
- With studio add the field display_name in the view
- Try to create a new product

Bug:

A access error was raised because a read was made on a record in cache

opw:2070074

closes odoo/odoo#37133

X-original-commit: 90143c18f50ff31ded5aba7d7ba3beb66423ff06
Signed-off-by: Simon Goffin (sig) <sig@openerp.com>

addons/product/models/product_template.py

@@ -400,7 +400,7 @@ class ProductTemplate(models.Model):
     @api.multi
     def name_get(self):
         # Prefetch the fields used by the `name_get`, so `browse` doesn't fetch other fields
-        self.read(['name', 'default_code'])
+        self.browse(self.ids).read(['name', 'default_code'])
         return [(template.id, '%s%s' % (template.default_code and '[%s] ' % template.default_code or '', template.name))
                 for template in self]