net: sched: act_police: fix sparse errors in tcf_police_dump()

Fixes following sparse errors:

net/sched/act_police.c:360:28: warning: dereference of noderef expression
net/sched/act_police.c:362:45: warning: dereference of noderef expression
net/sched/act_police.c:362:45: warning: dereference of noderef expression
net/sched/act_police.c:368:28: warning: dereference of noderef expression
net/sched/act_police.c:370:45: warning: dereference of noderef expression
net/sched/act_police.c:370:45: warning: dereference of noderef expression
net/sched/act_police.c:376:45: warning: dereference of noderef expression
net/sched/act_police.c:376:45: warning: dereference of noderef expression

Fixes: d1967e49

 ("net_sched: act_police: add 2 new attributes to support police 64bit rate and peakrate")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>