[FIXED] typos in comments

Fixed following typos:

.\bench\bench.go:39: agregating ==> aggregating
.\bench\bench.go:159: meessages ==> messages
.\bench\benchlib_test.go:119: througput ==> throughput

bench/bench.go

@@ -36,7 +36,7 @@ type Sample struct {
 	End       time.Time
 }
 
-// SampleGroup for a number of samples, the group is a Sample itself agregating the values the Samples
+// SampleGroup for a number of samples, the group is a Sample itself aggregating the values the Samples
 type SampleGroup struct {
 	Sample
 	Samples []*Sample
@@ -156,7 +156,7 @@ func (s *Sample) Throughput() float64 {
 	return float64(s.MsgBytes) / s.Duration().Seconds()
 }
 
-// Rate of meessages in the job per second
+// Rate of messages in the job per second
 func (s *Sample) Rate() int64 {
 	return int64(float64(s.JobMsgCnt) / s.Duration().Seconds())
 }