cons_tres: fix some logic to spread job across sockets

This fixes a couple of bugs in commit 0e4874e19490a24
1. round up core count for job as needed (i.e. if job needs 3
   CPUs per task and there are 2 CPUs per core, the job needs
   2 cores rather than 1)
2. fix some bad logic of available cores on socket 0 is 0
3. failed to set exit_code to 1 on a expect test failure