Object replicator still replicate a single partition even when max connection reached on remote node

[Alan Jiang]

When the object node's rsync max connection is reached, the REPLICATE request is still going to
be sent to the remote object node to replicate the single partition regardless the sync function failed.

This caused unnecessary load on the remote object nodes which potentially increase the object
server latency.

The update_delete() function in swift/swift/obj/replicator.py handles the sync failure properly
and it only send the REPLICATE request if sync is successful. Needs to handle the sync() return
code in the similar way.

[Alan Jiang (ajiang)]

                      hashed, recalc_hash = tpool_reraise(
                        get_hashes,
                        job['path'], recalculate=suffixes,
                        reclaim_age=self.reclaim_age)
                    self.logger.update_stats('suffix.hashes', hashed)
                    local_hash = recalc_hash
                    suffixes = [suffix for suffix in local_hash if
                                local_hash[suffix] !=
                                remote_hash.get(suffix, -1)]
                    success, _junk = self.sync(node, job, suffixes) <<<<<<<<<<<<<<<<<<<<
                   >>>>> Need to inspect success and only call REPLICATE if sync successfully <<<<<<<<<<<<
                    with Timeout(self.http_timeout):
                        conn = http_connect(
                            node['replication_ip'], node['replication_port'],
                            node['device'], job['partition'], 'REPLICATE',
                            '/' + '-'.join(suffixes),
                            headers=self.headers)
                        conn.getresponse().read()
                    # add only remote region when replicate succeeded
                    if success and node['region'] != job['region']:
                        synced_remote_regions.add(node['region'])
                    self.suffix_sync += len(suffixes)
                    self.logger.update_stats('suffix.syncs', len(suffixes))