FIX for SDL-4927: CFRetain+CFRelease a game controller's IOKit object

This fixes a crash whereby SDL could crash on macOS/Darwin, if and when a
USB game controller gets unplugged.  SDL was not retaining a reference
to the controller's OS/IOKit-provided 'device object', and was capable
of trying to use it, after a device was hot-unplugged.
1 file changed