drm/i915/guc: Fix issues with live_preempt_cancel

Having semaphores results in different behavior when a dependent request
is cancelled. In the case of semaphores the request could be on the HW
and complete successfully while without the request is held in the
driver and the error from the dependent request is propagated. Fix
live_preempt_cancel to take this behavior into account.

Also update live_preempt_cancel to use new function intel_context_ban
rather than intel_context_set_banned.

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220728024225.2363663-3-John.C.Harrison@Intel.com