After request id is checked in validate_rx_req_id() its value is still
used in the line
rx_ring->free_ids[next_to_clean] =
rx_ring->ena_bufs[i].req_id;
even if it was found to be out-of-bound for the array free_ids.
The patch moves the request id to an earlier stage in the napi routine and
makes sure its value isn't used if it's found out-of-bounds.