I have a buggy system which reports a udev "change" event for an empty
USB-C port every 0.14 seconds, which causes annoying frame hitches
because SDL decides that means it needs to do a libusb hid_enumerate,
which is slow (~25ms!) because of the get_usb_string() calls in there.
We only need to re-enumerate if we've seen a device added or removed, so
let's filter out the change event first.
Signed-off-by: Steven Noonan <steven@valvesoftware.com>
Signed-off-by: Sam Lantinga <slouken@libsdl.org>
4535d65491