[FIX] stock: default quantity to return
[FIX] stock: default quantity to return

The code was wrongly always taking the reserved quantity on the already
returned moves, but if they're done their value is zero.

task-2291973

closes odoo/odoo#54803

X-original-commit: 7b08f0ae0a39e8f575b21e744de16264b6365704
Signed-off-by: Simon Lejeune (sle) <1969d8dff896674c2d819e813f5e88ca826229ab@openerp.com>

ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo