datastore: Adjust error reporting to ensure database cleanup
datastore: Adjust error reporting to ensure database cleanup

Adjust DeleteStorageAttachment() and DeletePool() to not return errors
immediately so that database doesn't get out of sync with cache.

Signed-off-by: Rob Bradford <c49e1dc14cd52e2644816db47123896e0ac79025@intel.com>

markdryan/ciao,tpepper/ciao,ciao-project/ciao,01org/ciao,mcastelino/ciao,rbradford/ciao,tpepper/ciao,tpepper/ciao,markdryan/ciao,rbradford/ciao,ciao-project/ciao,01org/ciao,kaccardi/ciao,kaccardi/ciao,mcastelino/ciao,mcastelino/ciao