I believe there was a O(n^2) device walking issues on startup
- MaybeAddDevice gets called for every device at startup
- MaybeAddDevice calls IsJoystick
- IsJoystick calls SDL_UDEV_GetProductInfo
- SDL_UDEV_GetProductInfo calls udev_enumerate_scan_devices
- udev_enumerate_scan_devices walks all the devices
Prior to commit 3b1e0e1 this was mostly masked as IsJoystick only
called SDL_UDEV_GetProductInfo when a JSIOCGNAME ioctl was
successful. This fixes the O(n^2) behaviour by directly getting
the device via udev_device_new_from_devnum (based on type, major,
and minor number) instead of enumerating everything via
udev_enumerate_scan_devices and matching on name.
(cherry picked from commit 6e1611cc77)