fix: reference variable in pricing rule (#24711)

diff --git a/erpnext/accounts/doctype/pricing_rule/pricing_rule.py b/erpnext/accounts/doctype/pricing_rule/pricing_rule.py
index 0565264..f0b4e29 100644
--- a/erpnext/accounts/doctype/pricing_rule/pricing_rule.py
+++ b/erpnext/accounts/doctype/pricing_rule/pricing_rule.py
@@ -136,7 +136,7 @@
 			for d in self.items:
 				max_discount = frappe.get_cached_value("Item", d.item_code, "max_discount")
 				if max_discount and flt(self.discount_percentage) > flt(max_discount):
-					throw(_("Max discount allowed for item: {0} is {1}%").format(self.item_code, max_discount))
+					throw(_("Max discount allowed for item: {0} is {1}%").format(d.item_code, max_discount))
 
 	def validate_price_list_with_currency(self):
 		if self.currency and self.for_price_list: