netfilter: nf_tables: add forward expression to the netdev family

You can use this to forward packets from ingress to the egress path of
the specified interface. This provides a fast path to bounce packets
from one interface to another specific destination interface.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index 5c991335..6913454 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -95,6 +95,7 @@
 
 # nf_tables netdev
 obj-$(CONFIG_NFT_DUP_NETDEV)	+= nft_dup_netdev.o
+obj-$(CONFIG_NFT_FWD_NETDEV)	+= nft_fwd_netdev.o
 
 # generic X tables 
 obj-$(CONFIG_NETFILTER_XTABLES) += x_tables.o xt_tcpudp.o