netfilter: flowtable: Fix missing flush hardware on table free

netfilter: flowtable: Fix missing flush hardware on table free

commit 0f34f30a1be80f3f59efeaab596396bc698e7337 upstream.

If entries exist when freeing a hardware offload enabled table,
we queue work for hardware while running the gc iteration.

Execute it (flush) after queueing.

Fixes: c29f74e0df7a ("netfilter: nf_flow_table: hardware offload support")
Signed-off-by: Paul Blakey <paulb@mellanox.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>