net: sched: cls_cgroup need tcf_exts_init in all cases

This ensures the tcf_exts_init() is called for all cases.

Fixes: 952313bd

 ("net: sched: cls_cgroup use RCU")
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>