These two were sideeffects of lastSlave being in the same field as the
master. For devices generated by the master device directly, lastSlave was 0
and the device would (with the old checks) be interpreted as floating.
Add the required checks to safeguard against master devices.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Benjamin Tissoires <tissoire@cena.fr>