While I agree with the change for stmmac_tso_xmit(), please explain why
the change in stmmac_free_tx_buffer() is necessary.

It seems to me that if this is missing in stmmac_free_tx_buffer(), the
driver should have more problems than just TSO.

The change in stmmac_free_tx_buffer() is intended to be generic for all
users of last_segment, not only for the TSO path.

So far, I have not observed any issues with stmmac_xmit() or
stmmac_xdp_xmit_xdpf(), but this change ensures consistent and correct
handling of last_segment across all relevant transmit paths.

Thanks
Tao Wang