Skip testing multilocale lammps/lsms files under comm=none.

These sets of tests:

  studies/lammps/shemmy/p-lammps-n1
  studies/lammps/shemmy/p-lammps-n2
  studies/lammps/shemmy/p-lammps-n4

and

  studies/lsms/shemmy/lsms-parallel-n1
  studies/lsms/shemmy/lsms-parallel-n2
  studies/lsms/shemmy/lsms-parallel-n4

differ only in .numlocales. So:

* skip ...-n2 and ...-n4 under comm=none
* make ...-n2 and ...-n4 files symlinks to ...-n1,
  to emphasize their same-ness.

When our testing system supports multiple numlocales for a single test,
the symlinks can just be deleted.