Remove double hostPort field in log (#675)
Remove double hostPort field in log (#675)

Currently, we add the hostPort field to the channel logger, then add it
again inline in the log call.

This doesn't cause an issue for most users as they use logrus/similar
loggers which use a map for fields. However, when using zap, this ends
up logging the same field multiple times.
uber/tchannel-go,uber/tchannel-go