memorydb: Remove unused workload related code
memorydb: Remove unused workload related code

After the change to support tenant workloads and the CNCI changes that
required some code got orphaned in memorydb.go

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

tpepper/ciao,ciao-project/ciao,matthewrsj/ciao,01org/ciao,rbradford/ciao,erick0z/ciao,erick0z/ciao,matthewrsj/ciao,markdryan/ciao,mrkz/ciao,matthewrsj/ciao,obedmr/ciao,mrkz/ciao,01org/ciao,mcastelino/ciao,ciao-project/ciao,tpepper/ciao,erick0z/ciao,tpepper/ciao,obedmr/ciao,rbradford/ciao,kaccardi/ciao,obedmr/ciao,mcastelino/ciao,mrkz/ciao,markdryan/ciao,kaccardi/ciao,mcastelino/ciao