build: address -Werror,-Wcovered-switch-default error
The switch is fully covered over the enumeration and newer clang object
to the `default` cause in such a situation.  Remove the `default` case,
which should have no functional change.
@@ -542,8 +542,6 @@ dispatch_queue_attr_make_with_autorelease_frequency(dispatch_queue_attr_t dqa,
case DISPATCH_AUTORELEASE_FREQUENCY_WORK_ITEM:
case DISPATCH_AUTORELEASE_FREQUENCY_NEVER:
break;
- default:
- return (dispatch_queue_attr_t)dqa;
}
dispatch_queue_attr_info_t dqai = _dispatch_queue_attr_to_info(dqa);
dqai.dqai_autorelease_frequency = (uint16_t)frequency;
