[FIX] stock: manage mrp_operation picking type with fallback

mrp_operation picking type is not handle by default in stock module get_description function.

Add default return to stock get_description function

opw-3232811

closes odoo/odoo#115310

Signed-off-by: Tiffany Chang <tic@odoo.com>

addons/stock/models/product.py

@@ -208,6 +208,7 @@ class Product(models.Model):
             return self.description_pickingout or self.name
         if picking_code == 'internal':
             return self.description_picking or description
+        return description
 
     def _get_domain_locations(self):
         '''