Fix loop back tests
Fix loop back tests

The tests do not work when run concurrently.

Signed-off-by: Tony Asleson <1ef2d381aa56d512126ddaacc29e68136e4fdf55@redhat.com>

stratis-storage/stratisd,trgill/stratisd,mulkieran/stratisd,stratis-storage/stratisd,mulkieran/stratisd,stratis-storage/stratisd,trgill/stratisd