Fix for incremental backup metric ID bug
Fix for incremental backup metric ID bug

Small fix to ensure backing store shows up in metric ID.

Change-Id: Idc5dfecf50ca4521d7cc8d8ceb45ac813f06bb13
Reviewed-on: http://review.couchbase.org/111647
Tested-by: Build Bot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Carlos Gonzalez <36e622408f153c22cbe9b942c093fb5a1daab1e3@couchbase.com>

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