converted local_process_batch into tail call recusion
converted local_process_batch into tail call recusion

Change-Id: If7e9e88b3d9294320a90de14a172df718297ba43
Reviewed-on: http://review.couchbase.org/37558
Tested-by: Aliaksey Kandratsenka <340b8e09ca65cd3fc686427fcfed17e87eaf61e2@gmail.com>
Reviewed-by: Aliaksey Artamonau <3c875bcfb3adf2a65b2ae7686ca921e6c9433147@gmail.com>

nimishzynga/ns_server,ceejatec/ns_server,nimishzynga/ns_server,membase/ns_server,t3rm1n4l/ns_server,mschoch/ns_server,t3rm1n4l/ns_server,t3rm1n4l/ns_server,ceejatec/ns_server,t3rm1n4l/ns_server,membase/ns_server,mschoch/ns_server,ceejatec/ns_server,nimishzynga/ns_server,nimishzynga/ns_server,mschoch/ns_server,membase/ns_server,ceejatec/ns_server,mschoch/ns_server,mschoch/ns_server,mschoch/ns_server,ceejatec/ns_server,nimishzynga/ns_server,membase/ns_server,ceejatec/ns_server,membase/ns_server,t3rm1n4l/ns_server,membase/ns_server,nimishzynga/ns_server