net: sched: cls_u32: get rid of tp_c

Both hnode ->tp_c and tp_c argument of u32_set_parms()
the latter is redundant, the former - never read...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>