route: Set orig_output when redirecting to lwt on locally generated traffic

orig_output for IPv4 was only set for dsts which hit an input route.
Set it consistently for locally generated traffic as well to allow
lwt to continue the dst_output() path as configured by the nexthop.

Fixes: 2536862311d ("lwt: Add support to redirect dst.input")
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/route.c

@@ -2155,8 +2155,10 @@ add:
 	}
 
 	rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
-	if (lwtunnel_output_redirect(rth->dst.lwtstate))
+	if (lwtunnel_output_redirect(rth->dst.lwtstate)) {
+		rth->dst.lwtstate->orig_output = rth->dst.output;
 		rth->dst.output = lwtunnel_output;
+	}
 
 	return rth;
 }