[FIX] point_of_sale: apply extended cash box behavior properly

Normally when you manually add or remove money from the cashbox the
reference on the bank statement line should be set to the name of the
session. But because the wrong function names where used this didn't
happen. Introduced by f5ad2516.

Fixes #12224

addons/point_of_sale/wizard/pos_box.py

@@ -29,12 +29,12 @@ class PosBox(CashBox):
 class PosBoxIn(PosBox):
     _inherit = 'cash.box.in'
 
-    def _compute_values_for_statement_line(self, cr, uid, box, record, context=None):
+    def _calculate_values_for_statement_line(self, cr, uid, id, record, context=None):
         
         if context is None:
             context = {}
     
-        values = super(PosBoxIn, self)._compute_values_for_statement_line(cr, uid, box, record, context=context)
+        values = super(PosBoxIn, self)._calculate_values_for_statement_line(cr, uid, id, record, context=context)[0]
 
         active_model = context.get('active_model', False) or False
         active_ids = context.get('active_ids', []) or []
@@ -49,8 +49,8 @@ class PosBoxIn(PosBox):
 class PosBoxOut(PosBox):
     _inherit = 'cash.box.out'
 
-    def _compute_values_for_statement_line(self, cr, uid, box, record, context=None):
-        values = super(PosBoxOut, self)._compute_values_for_statement_line(cr, uid, box, record, context=context)
+    def _calculate_values_for_statement_line(self, cr, uid, id, record, context=None):
+        values = super(PosBoxOut, self)._calculate_values_for_statement_line(cr, uid, id, record, context=context)[0]
 
         active_model = context.get('active_model', False) or False
         active_ids = context.get('active_ids', []) or []