Steps to reproduce:

1. Download and open the attached project
2. Make sure you have any controllers connected
3. Enter Playmode
4. Observe logs of connected controllers
5. Exit Playmode
6. Disconnect controllers
7. Enter Playmode

Expected result: console logs no controllers connected
Actual result: console logs any controllers that were connected before

Reproduced 5.5.0f1, 5.6.4f1*, 2017.1.2f1, 2017.2.0f3, 2017.3.0b4, 2018.2.0a3

Notes:
- The issue is more prominent with VR controllers - it logs the name of the one connected before. For regular controllers, it still returns Input.GetJoystickNames().length as the number connected originally
- 5.6 does not log names, but still incorrectly detects number of connected controllers