net: sctp: probe: allow more advanced ingress filtering by mark

This is a follow-up commit for commit b1dcdc68 ("net: tcp_probe:
allow more advanced ingress filtering by mark") that allows for
advanced SCTP probe module filtering based on skb mark (for a more
detailed description and advantages using mark, refer to b1dcdc68

).
The current option to filter by a given port is still being preserved.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>