net: sched: rename QDISC_DROP_CAKE_FLOOD to QDISC_DROP_FLOOD_PROTECTION

net: sched: rename QDISC_DROP_CAKE_FLOOD to QDISC_DROP_FLOOD_PROTECTION

Rename QDISC_DROP_CAKE_FLOOD to QDISC_DROP_FLOOD_PROTECTION to use a
generic name without embedding the qdisc name. This follows the
principle that drop reasons should describe the drop mechanism rather
than being tied to a specific qdisc implementation.

The flood protection drop reason is used by qdiscs implementing
probabilistic drop algorithms (like BLUE) that detect unresponsive
flows indicating potential DoS or flood attacks. CAKE uses this via
its Cobalt AQM component.

Signed-off-by: Jesper Dangaard Brouer <hawk@kernel.org>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/177211347537.3011628.13759059534638729639.stgit@firesoul
Signed-off-by: Jakub Kicinski <kuba@kernel.org>