elanspi: Fix assertion fail when deactivating during AWAIT_FINGER_UP

The gnome UI for enrolling fingerprints seems to explicitly stop enrollment as soon as the final image is reported, which ends up occurring while the sensor is still capturing. The result is the sensor winds up in the idle state while it's still finishing its last image capture which ends up triggering an assert and crashing fprintd. This adds some checks to fix that as well as another cancellation-related error message.