Fixes a race in the logstream. (#1586)
Fixes a race in the logstream. (#1586)

`eg.Wait` cannot be called before `eg.Go` without tripping Go's race detection.

Internally errgroup uses sync.Wait, which has [the following](https://godoc.org/sync#WaitGroup.Add) warning:

> Note that calls with a positive delta that occur when the counter is zero must happen before a Wait

When `eg.Go` isn't clearly called prior to `eg.Wait` the read of the error field in `eg.Wait` races with the
assignment of the error field in the once of `eg.Go`.
knative/pkg,knative/pkg