bpf: make bpf_skb_ecn_set_ce callable from BPF_PROG_TYPE_SCHED_ACT

This helper is useful if a bpf tc filter sets skb->tstamp.
Signed-off-by: Peter Oskolkov <posk@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

net/core/filter.c

@@ -5959,6 +5959,8 @@ tc_cls_act_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return &bpf_skc_lookup_tcp_proto;
 	case BPF_FUNC_tcp_check_syncookie:
 		return &bpf_tcp_check_syncookie_proto;
+	case BPF_FUNC_skb_ecn_set_ce:
+		return &bpf_skb_ecn_set_ce_proto;
 #endif
 	default:
 		return bpf_base_func_proto(func_id);