evdev: drop the button count when releasing keys on remove

evdev: drop the button count when releasing keys on remove

We previously called this function only before device removal, so failing to
update the button state didn't matter. To make this function generic for the
device suspend/resume, we need to keep track of the button/key count properly.

If we have a key down multiple times on suspend though, log a bug.
The dispatch should release the keys before we even get here (functionality
added in a subsequent patch).

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>