drm/i915: Do not check crtc_state->active in intel_color_load_luts.

This is already tested by its callers.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459350996-4957-3-git-send-email-maarten.lankhorst@linux.intel.com