chore: minor code cleanup (#38615)

diff --git a/erpnext/stock/doctype/stock_reconciliation/stock_reconciliation.js b/erpnext/stock/doctype/stock_reconciliation/stock_reconciliation.js
index b3998b7..8e9dcb0 100644
--- a/erpnext/stock/doctype/stock_reconciliation/stock_reconciliation.js
+++ b/erpnext/stock/doctype/stock_reconciliation/stock_reconciliation.js
@@ -209,7 +209,7 @@
 
 	set_amount_quantity: function(doc, cdt, cdn) {
 		var d = frappe.model.get_doc(cdt, cdn);
-		if (d.qty & d.valuation_rate) {
+		if (d.qty && d.valuation_rate) {
 			frappe.model.set_value(cdt, cdn, "amount", flt(d.qty) * flt(d.valuation_rate));
 			frappe.model.set_value(cdt, cdn, "quantity_difference", flt(d.qty) - flt(d.current_qty));
 			frappe.model.set_value(cdt, cdn, "amount_difference", flt(d.amount) - flt(d.current_amount));