go: direct client concurrency
go: direct client concurrency

Fix up the concurrency in firstResponse/quorumResponse, because
there's a bug in it and also I'm better at it now.

Change-Id: Ib438d747e6f0a0783e2748a0681ab7c3d56bf52f

corystone/hummingbird,corystone/hummingbird,creiht/hummingbird,redbo/hummingbird,troubling/hummingbird,creiht/hummingbird,nadeemsyed/hummingbird,nadeemsyed/hummingbird,troubling/hummingbird,redbo/hummingbird