fm10k_fifo_crc
mbx->local = fm10k_fifo_crc(&mbx->tx, head, len, mbx->local);
mbx->remote = fm10k_fifo_crc(fifo, offset, len, mbx->remote);
crc = fm10k_fifo_crc(fifo, fm10k_fifo_head_offset(fifo, mbx->pulled),