net/sched: act_police: re-use tcf_tm_dump()

Use tcf_tm_dump(), instead of an open coded variant (no functional change
in this patch).

Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>