jb linker.c : Fix fd leak in nullify_closed_stdio

Signed-off-by: Philippe De Swert <philippe.deswert@jollamobile.com>
Fix warning due to missing include

Signed-off-by: Philippe De Swert <philippe.deswert@jollamobile.com>
property_set does not return anything, so changing it to
 return 0

Signed-off-by: Philippe De Swert <philippe.deswert@jollamobile.com>