Avoid extra hop to stats_reader when getting stats in ns_heart.
Avoid extra hop to stats_reader when getting stats in ns_heart.

Change-Id: I77ab8fa2fbc0bc3f2e9f178e32258e437a39c45c
Reviewed-on: http://review.couchbase.org/49620
Reviewed-by: Aliaksey Artamonau <3c875bcfb3adf2a65b2ae7686ca921e6c9433147@gmail.com>
Tested-by: Aliaksey Artamonau <3c875bcfb3adf2a65b2ae7686ca921e6c9433147@gmail.com>

membase/ns_server,mschoch/ns_server,ceejatec/ns_server,nimishzynga/ns_server,membase/ns_server,mschoch/ns_server,mschoch/ns_server,membase/ns_server,ceejatec/ns_server,nimishzynga/ns_server,membase/ns_server,ceejatec/ns_server,ceejatec/ns_server,membase/ns_server,ceejatec/ns_server,nimishzynga/ns_server,nimishzynga/ns_server,mschoch/ns_server,mschoch/ns_server,nimishzynga/ns_server,ceejatec/ns_server,mschoch/ns_server,nimishzynga/ns_server,membase/ns_server