This patch adds missing role attribute to the DCCP type, otherwise
the creation of entries is not of any use.

The attribute added is CTA_PROTOINFO_DCCP_ROLE which contains the
role of the conntrack original tuple.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NPatrick McHardy <kaber@trash.net>