modify misleading note in comment
now rdbSaveInfo used in both way, so i think we should update previous notes, in case of misleading
@@ -1229,7 +1229,7 @@ struct redisMemOverhead {
* order to implement additional functionalities, by storing and loading
* metadata to the RDB file.
*
- * Currently the only use is to select a DB at load time, useful in
+ * For example, to use select a DB at load time, useful in
* replication in order to make sure that chained slaves (slaves of slaves)
* select the correct DB and are able to accept the stream coming from the
* top-level master. */
