There has been a lot of issues reported for Photshop CC 2015 crashing while closing. So if you are encountering the same issue please try the below steps.
1. Launch Photoshop and click on edit>preferences>performance and uncheck the graphic processor.
2. Close Photoshop and relaunch to check if it still crashes.
3. If the above step works, go the graphic card manufacturer's website and install the latest drivers from there. Restart the machine and launch Photoshop and check the graphic processor option.