fix: incorrect expense account book in purchase return

(cherry picked from commit 2a720e7008)

erpnext/stock/doctype/purchase_receipt/purchase_receipt.py

@@ -724,6 +724,9 @@ class PurchaseReceipt(BuyingController):
 					or stock_asset_rbnb
 				)
 
+				if self.is_return and item.expense_account:
+					loss_account = item.expense_account
+
 				cost_center = item.cost_center or frappe.get_cached_value(
 					"Company", self.company, "cost_center"
 				)