MB-100 remove unused node_storage_info function

Change-Id: Ibdc9a6cd96aafe97b877c3ead539bdb6fe2275ae
Reviewed-on: http://review.couchbase.org/32529
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>