libafs: kill rxevent daemon even in upcall mode

libafs: kill rxevent daemon even in upcall mode

the switch from rxk listener env to upcall env could leave the event
daemon running. fix that.

Reviewed-on: http://gerrit.openafs.org/6713
Reviewed-by: Jeffrey Altman <jaltman@secure-endpoints.com>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementix.org>
(cherry picked from commit a4d9fbaa8036cc78ae0119330314f6deab159c90)

Change-Id: I2e87c692ee2003a24590f700accc30704899db8b
Reviewed-on: http://gerrit.openafs.org/6759
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Alistair Ferguson <alistair.ferguson@mac.com>
Reviewed-by: Derrick Brashear <shadow@dementix.org>