drm/i915: Mark the GPU as wedged without error on fault injection

If we have been instructed (by CI) to inject a fault to load the module
with a wedged GPU, do so quietly less we upset CI.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Michał Winiarski <michal.winiarski@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180607134558.31150-1-chris@chris-wilson.co.uk