net: ethernet: rtsn: fix potential memory leak in rtsn_start_xmit()

The rtsn_start_xmit() returns NETDEV_TX_OK without freeing skb
in case of skb->len being too long, add dev_kfree_skb_any() to fix it.

Fixes: b0d3969d ("net: ethernet: rtsn: Add support for Renesas Ethernet-TSN")
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241014144250.38802-1-wanghai38@huawei.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>