net: bcmgenet: fix leaking free_bds

net: bcmgenet: fix leaking free_bds

While reclaiming the tx queue we fast forward the write pointer to
drop any data in flight. These dropped frames are not added back
to the pool of free bds. We also need to tell the netdev that we
are dropping said data.

Fixes: f1bacae8b655 ("net: bcmgenet: support reclaiming unsent Tx packets")
Signed-off-by: Justin Chen <justin.chen@broadcom.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>
Tested-by: Nicolai Buchwitz <nb@tipi-net.de>
Link: https://patch.msgid.link/20260406175756.134567-3-justin.chen@broadcom.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>