arealights: minor cleanup.
arealights: minor cleanup.

mosra/magnum-examples,mosra/magnum-examples,mosra/magnum-examples,Squareys/magnum-examples,Squareys/magnum-examples,mosra/magnum-examples,Squareys/magnum-examples,mosra/magnum-examples,Squareys/magnum-examples,mosra/magnum-examples,mosra/magnum-examples