[FIX] Lost pack operation link with stock move when splitting

When we want to split pack operation quantities, the resulting pack operation
does not contain the link with corresponding stock_move.
Recomputing remaining quantities fixes that issue.

addons/stock/models/stock_pack_operation.py

@@ -165,6 +165,8 @@ def split_quantities(self):
                 cpy = operation.copy(default={'qty_done': 0.0, 'product_qty': operation.product_qty - operation.qty_done})
                 operation.write({'product_qty': operation.qty_done})
                 operation._copy_remaining_pack_lot_ids(cpy)
+                if operation.picking_id:
+                    operation.picking_id.recompute_remaining_qty()
             else:
                 raise UserError(_('The quantity to split should be smaller than the quantity To Do.  '))
         return True