refactor: simplify conditional logic

Command: `sourcery review --fix --enable de-morgan .`
diff --git a/erpnext/stock/stock_ledger.py b/erpnext/stock/stock_ledger.py
index 9142a27..9203f45 100644
--- a/erpnext/stock/stock_ledger.py
+++ b/erpnext/stock/stock_ledger.py
@@ -1711,7 +1711,7 @@
 def validate_negative_qty_in_future_sle(args, allow_negative_stock=False):
 	if allow_negative_stock or is_negative_stock_allowed(item_code=args.item_code):
 		return
-	if not (args.actual_qty < 0 or args.voucher_type == "Stock Reconciliation"):
+	if args.actual_qty >= 0 and args.voucher_type != "Stock Reconciliation":
 		return
 
 	neg_sle = get_future_sle_with_negative_qty(args)