wire: remove special zero-key handling.

We used to use a hack for gossip_resolve_channel_reply, where we'd send
a NULL key on failure.  It's now been neatened to use a counter, so we
don't need this.

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

wire/fromwire.c

@@ -100,10 +100,7 @@ void fromwire_pubkey(const u8 **cursor, size_t *max, struct pubkey *pubkey)
 	if (!fromwire(cursor, max, der, sizeof(der)))
 		return;
 
-	/* FIXME: Handing dummy keys through here is dumb.
-	 * See towire_gossip_resolve_channel_reply --RR */
-	if (!memeqzero(der, sizeof(der))
-	    && !pubkey_from_der(der, sizeof(der), pubkey))
+	if (!pubkey_from_der(der, sizeof(der), pubkey))
 		fromwire_fail(cursor, max);
 }
 

wire/towire.c

@@ -50,12 +50,9 @@ void towire_pubkey(u8 **pptr, const struct pubkey *pubkey)
 	u8 output[PUBKEY_DER_LEN];
 	size_t outputlen = sizeof(output);
 
-	if (pubkey)
 	secp256k1_ec_pubkey_serialize(secp256k1_ctx, output, &outputlen,
 				      &pubkey->pubkey,
 				      SECP256K1_EC_COMPRESSED);
-	else
-		memset(output, 0, sizeof(output));
 
 	towire(pptr, output, outputlen);
 }