drm/i915: Fix stale comment about I915_RESET_IN_PROGRESS flag

It has been replaced by I915_RESET_BACKOFF / I915_RESET_HANDOFF.

Signed-off-by: Michel Thierry <michel.thierry@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170418202335.35232-2-michel.thierry@intel.com


Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>