[FIX] point_of_sale: fix forward port of currency displaying

This fixes the forward port of 5c9b4556e3
from saas-6, which was forward ported to 9.0 in
56a442e205.

addons/point_of_sale/static/src/js/widget_base.js

@@ -6,7 +6,6 @@ var utils = require('web.utils');
 var Widget = require('web.Widget');
 
 var round_di = utils.round_decimals;
-var round_pr = utils.round_precision;
 
 // This is a base class for all Widgets in the POS. It exposes relevant data to the 
 // templates : 
@@ -43,11 +42,6 @@ var PosBaseWidget = Widget.extend({
             decimals = this.pos.dp[precision];
         }
 
-        this.format_currency_no_symbol = function(amount){
-            amount = round_pr(amount,currency.rounding);
-            amount = amount.toFixed(decimals);
-            return amount;
-        };
         if (typeof amount === 'number') {
             amount = round_di(amount,decimals).toFixed(decimals);
             amount = formats.format_value(round_di(amount, decimals), { type: 'float', digits: [69, decimals]});