[NET_SCHED]: sch_ingress: remove useless printk

The printk about ingress qdisc registration error can't be triggered
under normal circumstances. Since register_qdisc only fails for two
identical registrations, the only way to trigger it is by loading the
sch_ingress modules multiple times under different names, in which
case we already return -EEXIST to userspace.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Acked-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>