isl_input.c: resolve_paren_expr: reuse push_aff
isl_input.c: resolve_paren_expr: reuse push_aff

This removes some code duplication.

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

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