ciao-controller: datastore: check instance ID when updating attachment
ciao-controller: datastore: check instance ID when updating attachment

Do not delete attachments based on stats without first checking
the instance ID.  This fixes a bug which caused the attachment
list to get deleted whenever a node with no volumes attached sent
stats.

Signed-off-by: Kristen Carlson Accardi <047ff8258f0113ece56e5e2fe9e0d987b14c4333@linux.intel.com>

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