CBPS-961 report num_storage_instances instead of num_indexes
CBPS-961 report num_storage_instances instead of num_indexes

Change-Id: Ifb76c223c5dd5b301118c813aa37b6b19c47e81b
Reviewed-on: https://review.couchbase.org/c/perfrunner/+/165981
Tested-by: Build Bot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: vikas chaudhary <c251871a64d7d31888eace0406cb3d4c419d5f73@couchbase.com>

couchbase/perfrunner,couchbase/perfrunner,couchbase/perfrunner,couchbase/perfrunner,couchbase/perfrunner,couchbase/perfrunner