Log the flight in your next open line with the appropriate date. In the remarks write "Late Entry" and whatever else youd like. You dont have to write CFI Ride or failed ride or anything else you do not want to. Its on your pria, they know you failed so you dont have to reference that in your logbook if you do not want.
Source:
The Marine Corps likes to keep logbooks of everything. "Nothing new or unusual to report" written 400 times in a row over the course of 6 months. They have guidance for every possible logbook error/variation.