Make sure final value arrives to DoneCh() always

stopCh is already selected in renewAuth() and renewLease(), so this case block is not needed here and otherwise, it causes a race condition and sometimes the final result doesn't arrive in the DoneCh()

api/renewer.go

@@ -166,10 +166,7 @@ func (r *Renewer) Renew() {
 		result = r.renewLease()
 	}
 
-	select {
-	case r.doneCh <- result:
-	case <-r.stopCh:
-	}
+	r.doneCh <- result
 }
 
 // renewAuth is a helper for renewing authentication.