isl_multi_aff_from_aff_mat: plug memory leak on error path
isl_multi_aff_from_aff_mat: plug memory leak on error path

In particular, free the "space" argument in case any error occurs.

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

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