simplify code

Signed-off-by: He Xian <[email protected]>

v2/eventlog/eventlog.go

@@ -34,10 +34,13 @@ func NewRecent(sizelimit int) Recent {
 func (p *recent) Add(timestamp time.Time, message string) {
 	p.mu.Lock()
 	defer p.mu.Unlock()
-	if len(p.elements) > 0 && p.elements[len(p.elements)-1].message == message {
-		p.elements[len(p.elements)-1].tstamp = timestamp
-		p.elements[len(p.elements)-1].count++
-		return
+	if len(p.elements) > 0 {
+		last := &p.elements[len(p.elements)-1]
+		if last.message == message {
+			last.tstamp = timestamp
+			last.count++
+			return
+		}
 	}
 	p.elements = append(p.elements, entry{timestamp, message, 1})
 	if len(p.elements) >= 2*p.sizelimit {