As usual, mostly const char changes. However, filter_device_events had
a potentially uninitialized value, 'raw', which I added a bunch of
checks for. I suspect most of those are 'can't happen', but it's hard
to see that inside the function.
Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>