This test verifies the sdrWmKey feature by inspecting per-node SVR4
shared memory keys via `ipcs -m`.  On the Solaris 11 regression host
ION's working memory is not backed by SVR4 shm (segments do not
appear in `ipcs -m`), so the key-presence assertions cannot be
satisfied even though the underlying feature works (bping round-trips
between nodes still pass).  Run this test on Linux.
