flush_scheduled_work() is deprecated and scheduled to be removed.
technisat-usb2 already sync-cancels the only work item it uses and
there's no reason for it to call flush_scheduled_work().  Don't use
it.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Patrick Boettcher <pboettcher@kernellabs.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>