fix: standard formula to calculate the "difference" (#36612)

diff --git a/erpnext/accounts/doctype/pos_closing_entry/pos_closing_entry.js b/erpnext/accounts/doctype/pos_closing_entry/pos_closing_entry.js
index a6c0102..91e71e9 100644
--- a/erpnext/accounts/doctype/pos_closing_entry/pos_closing_entry.js
+++ b/erpnext/accounts/doctype/pos_closing_entry/pos_closing_entry.js
@@ -153,7 +153,7 @@
 frappe.ui.form.on('POS Closing Entry Detail', {
 	closing_amount: (frm, cdt, cdn) => {
 		const row = locals[cdt][cdn];
-		frappe.model.set_value(cdt, cdn, "difference", flt(row.expected_amount - row.closing_amount));
+		frappe.model.set_value(cdt, cdn, "difference", flt(row.closing_amount - row.expected_amount));
 	}
 })