drm/i915: remove parens around revision ids

Totally unnecessary.

Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1445343722-3312-1-git-send-email-jani.nikula@intel.com


Signed-off-by: Jani Nikula <jani.nikula@intel.com>