litroom() vs Blind

litroom() vs Blind

An item from the "A few bugs" mail was that reading a scroll of light
when swallowed didn't light the surrounding area--which is intended--
but that doing so while blind *did*.  The logic in litroom()--which
the report was based on--was wrong, but do_clear_area() prevented the
light was escaping the engulfer.  So there was no bug from the player's
perspective, but only because the vision code has special handling for
being swallowed.  This fixes litroom()'s logic and does some formatting
cleanup.