net-shapers: implement shaper cleanup on queue deletion

hook into netif_set_real_num_tx_queues() to cleanup any shaper
configured on top of the to-be-destroyed TX queues.

Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Link: https://patch.msgid.link/6da4ee03cae2b2a757d7b59e88baf09cc94c5ef1.1728460186.git.pabeni@redhat.com


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