Issue: create an immediate transfer, add a move and a done quantity, the
picking is in waiting state instead of ready.
Due to rev[0], the moves added in an immediate transfer have an initial
demand. After auto-confirming them, their state were 'confirmed' and not
'assigned'.
Solution: we force the state to assigned
[0] 8303b1a69e
closes odoo/odoo#39492
Signed-off-by: Simon Lejeune (sle) <sle@openerp.com>