drm/i915: Show guilty context name on GPU reset

We mention that we are resetting the GPU, and dump the device state for
post mortem debugging. However, while that dump contains the active
processes and the one flagged as causing the error, we do not always
include that information in dmesg. Include the name of the guilty
process in dmesg for reference.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191111114323.5833-4-chris@chris-wilson.co.uk