drm/i915/overlay: Remove redundant overlay->active
Now that we have overlay->frontbuffer_bits, overlay->active
is completely redundant, so remove it.
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20260226100738.29997-5-ville.syrjala@linux.intel.com