fix: Do not assume size_t == u64

This was causing some compilation trouble on 32bit systems, see #256.

Reported-by: @shsmith
Signed-off-by: Christian Decker <decker.christian@gmail.com>

onchaind/onchain.c

@@ -1286,7 +1286,7 @@ int main(int argc, char *argv[])
 		status_failed(WIRE_ONCHAIN_BAD_COMMAND,
 			      "Can't allocate %"PRIu64" htlcs", num_htlcs);
 
-	for (size_t i = 0; i < num_htlcs; i++) {
+	for (u64 i = 0; i < num_htlcs; i++) {
 		msg = wire_sync_read(ctx, REQ_FD);
 		if (!msg || !fromwire_onchain_htlc(msg, NULL, &htlcs[i]))
 			status_failed(WIRE_ONCHAIN_BAD_COMMAND,

wallet/wallet.c

@@ -31,7 +31,7 @@ bool wallet_add_utxo(struct wallet *w, struct utxo *utxo,
 	bool result = db_exec(
 	    __func__, w->db,
 	    "INSERT INTO outputs (prev_out_tx, prev_out_index, value, type, "
-	    "status, keyindex) VALUES ('%s', %d, %zu, %d, %d, %d);",
+	    "status, keyindex) VALUES ('%s', %d, %"PRIu64", %d, %d, %d);",
 	    hextxid, utxo->outnum, utxo->amount, type, output_state_available,
 	    utxo->keyindex);
 	tal_free(tmpctx);