Update forms.py
Update forms.py

Fixes wrong fieldname in StockRecord form.
sasha0/django-oscar,django-oscar/django-oscar,solarissmoke/django-oscar,solarissmoke/django-oscar,sasha0/django-oscar,sasha0/django-oscar,sasha0/django-oscar,django-oscar/django-oscar,solarissmoke/django-oscar,solarissmoke/django-oscar,django-oscar/django-oscar,django-oscar/django-oscar