isl_set_simple_hull: add memory management annotations
isl_set_simple_hull: add memory management annotations

This was missing from isl-0.02-112-g972d64f643 (doc: document
simple hull, Wed Apr 21 17:15:51 2010 +0200).

Signed-off-by: Sven Verdoolaege <235c10dd23b819f81cdc9756a251746bc184cab6@gmail.com>

Meinersbur/isl,Meinersbur/isl,Meinersbur/isl,Meinersbur/isl