This patch fixes the device removal order when a connection is closed, 
which allows HAL to see the remove event and prevents a bunch of 
duplicate devices from piling up and eventually hitting the limit for 
the for input devices in X.

Posting for discussion since I used a polling loop (with a sleep) to 
wait for child devices to go away. I assume it'd be preferable to wait 
in a more proper way. In that case, before I start, is this the right 
place to be waiting?