permute_tx: don't save permutation map.

We no longer need it anywhere.  This simplifies things to the point where
we might as well just not include dust outputs as we go, rather than
explicitly removing them, which gets rid of remove_dust.c as well.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

daemon/commit_tx.h

@@ -34,6 +34,5 @@ struct bitcoin_tx *create_commit_tx(const tal_t *ctx,
 				    struct peer *peer,
 				    const struct sha256 *rhash,
 				    const struct channel_state *cstate,
-				    enum htlc_side side,
-				    int **map);
+				    enum htlc_side side);
 #endif