etcd-tester: fix goword warnings

tools/functional-tester/etcd-tester/failure.go

@@ -39,7 +39,7 @@ type failure interface {
 	// Recover recovers the injected failure caused by the injection of the
 	// given round and wait for the recovery of the testing cluster.
 	Recover(c *cluster, round int) error
-	// return a description of the failure
+	// Desc returns a description of the failure
 	Desc() string
 }
 

tools/functional-tester/etcd-tester/stresser.go

@@ -161,8 +161,6 @@ type stresserV2 struct {
 	KeySuffixRange int
 
 	N int
-	// TODO: not implemented
-	Interval time.Duration
 
 	mu      sync.Mutex
 	failure int