prefetcher_test: No longer need the wait group since we introduced the sync channel to the prefetcher.
prefetcher_test: No longer need the wait group since we introduced the sync channel to the prefetcher.

keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/kbfs,keybase/client,keybase/client,keybase/client,keybase/kbfs,keybase/client,keybase/kbfs,keybase/client,keybase/client,keybase/kbfs