netfilter: flowtable: use correct direction to set up tunnel route

netfilter: flowtable: use correct direction to set up tunnel route

The layer 2 encapsulation and layer 3 tunnel information in the xmit
path is taken from the other tuple, because the tunnel information that
is included in the tuple for hashtable lookups is also used to perform
the egress encapsulation in the transmit path.

This patch uses the correct direction when setting up the tunnel, the
original proposed patch to address this fix uses the reversed direction.

While at it, remove the redundant check to call dst_release() to drop
the reference on the dst that was obtained from the forward path, which
is not useful in the direct xmit path unless tunneling is performed.

Fixes: fa7395c02d95 ("netfilter: flowtable: support IPIP tunnel with direct xmit")
Cc: stable@vger.kernel.org
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>