drm/i915: Make GEM errors non-fatal by default

While immensely convenient for developing to only tackle the first
error, and not be flooded by repeated or secondiary issues, many more
casual testers are not setup to remotely capture debug traces. For those
testers, it is more beneficial to keep the system running in the remote
chance that they are able to extract the original debug logs.

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/20210114113434.8229-2-chris@chris-wilson.co.uk