Both ServertimeBracketValues and IdleTimeBracketValues copy the value into
there SysCounter privates. Call it for a NULL set as well, so we don't end up
with stale pointers and we can remove the block/wakeup handlers.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Reviewed-by: Keith Packard <keithp@keithp.com>