interrupt RXBNEI is set, but the RX FIFO is empty
What happens:
- one frame is transmitted on the bus and the core receives it
- RXBNEI is set
- ISR clears the interrupt and reads the frame
- RXBNEI is set again, but the frame count in CTU_CAN_FD_RX_STATUS is 0 (should not happen)
- after clearing it, it is not set again until next frame reception
It is reproducible on the dev board. The RX interrupt handler prints debug messages to kernel log.