Use @transaction.atomic instead of @transaction.atomic()

src/pretix/base/services/locking.py

@@ -80,7 +80,7 @@ def lock_event_db(event):
     raise EventLock.LockTimeoutException()
 
 
-@transaction.atomic()
+@transaction.atomic
 def release_event_db(event):
     if not hasattr(event, '_lock') or not event._lock:
         raise EventLock.LockReleaseException('Lock is not owned by this thread')

src/pretix/base/services/orders.py

@@ -258,7 +258,7 @@ def _check_positions(event: Event, now_dt: datetime, positions: List[CartPositio
         raise OrderError(err)
 
 
-@transaction.atomic()
+@transaction.atomic
 def _create_order(event: Event, email: str, positions: List[CartPosition], now_dt: datetime,
                   payment_provider: BasePaymentProvider, locale: str=None):
     total = sum([c.price for c in positions])