CBQE-1040: do not print multi-get error0

in getq, a return of 0 means key was retrieved

Change-Id: I939def4c771c3edbe8c6640a135a134f3e5137f4
Reviewed-on: http://review.couchbase.org/24561
Reviewed-by: Ketaki Gangal <ketakigangal@gmail.com>
Tested-by: Ketaki Gangal <ketakigangal@gmail.com>