net/sched: Remove ipt action tests

Commit ba24ea12 ("net/sched: Retire ipt action") removed the ipt action
but not the testcases. This patch removes the outstanding tdc tests.

Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>