RXRPC_CALL_RTT_PEND_SHIFT
if (!test_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &avail))
clear_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
clear_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
set_bit(rtt_slot + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);