[FIX] mrp,stock: error w/o traceback on create warehouse

If a warehouse is created without code (eg. when created as a new group
from a kanban view grouped by warehouse) we would get a traceback
instead of an error:

```
  The operation cannot be completed:
  - Create/update: a mandatory field is not set.
  - Delete: another model requires the record being deleted. If possible, archive it instead.

  Model: Warehouse (stock.warehouse), Field: Short Name (code)
```

opw-2124162
fix #40233
closes #40267

closes odoo/odoo#40382

X-original-commit: b6caa179e17199b29a9ca4009c53acb378423926
Signed-off-by: Nicolas Lempereur (nle) <nle@odoo.com>

addons/mrp/models/stock_warehouse.py

@@ -188,7 +188,7 @@ class StockWarehouse(models.Model):
         values = super(StockWarehouse, self)._get_locations_values(vals, code=code)
         def_values = self.default_get(['manufacture_steps'])
         manufacture_steps = vals.get('manufacture_steps', def_values['manufacture_steps'])
-        code = vals.get('code') or code
+        code = vals.get('code') or code or ''
         code = code.replace(' ', '').upper()
         company_id = vals.get('company_id', self.company_id.id)
         values.update({

addons/stock/models/stock_warehouse.py

@@ -516,7 +516,7 @@ class Warehouse(models.Model):
         def_values = self.default_get(['reception_steps', 'delivery_steps'])
         reception_steps = vals.get('reception_steps', def_values['reception_steps'])
         delivery_steps = vals.get('delivery_steps', def_values['delivery_steps'])
-        code = vals.get('code') or code
+        code = vals.get('code') or code or ''
         code = code.replace(' ', '').upper()
         company_id = vals.get('company_id', self.default_get(['company_id'])['company_id'])
         sub_locations = {