made liblz16 happier on OpenOS when decompressing smaller files

lib/liblz16.lua

@@ -13,7 +13,7 @@ local function readBuffer(fi)
   if len < 1 then
    return nil
   end
-  coroutine.yield()
+  if os.sleep then os.sleep(0) else coroutine.yield() end
   return lz.decompress(fi:read(len))
  end
  function stream.close()