b=892

b=892
osc_close used to walk through the request list, trying to find the
corresponding osc_open.  This is slow, racy and doomed to failure, so we
need to instead save a point to the request in osc_open.

Instead of passing a handle up to whoever called us, pass 32 bytes of
opaque data.  These get passed back to us at various points, through
the obdo's inline field.