Revert "rados: Fix cache_flush, cache_try_flush, cache_evict and add hit_set_list"

cache_evict is kinda broken at the moment due to snapdir nonsense.  I'm reverting this
test for now until it's fixed so it doesn't obscure the test results.

Bug: 8629
This reverts commit 3dae48c7cd9e72af47bc76840df652c1570d7502.