tests/e2e: remove unnessary type conversion

Signed-off-by: Gyuho Lee <gyuhox@gmail.com>

tests/e2e/ctl_v3_alarm_test.go

@@ -37,7 +37,7 @@ func alarmTest(cx ctlCtx) {
 	}
 
 	// write some chunks to fill up the database
-	buf := strings.Repeat("b", int(os.Getpagesize()))
+	buf := strings.Repeat("b", os.Getpagesize())
 	for {
 		if err := ctlV3Put(cx, "2nd_test", buf, ""); err != nil {
 			if !strings.Contains(err.Error(), "etcdserver: mvcc: database space exceeded") {