Use increment operator

Signed-off-by: Alexandr Morozov <lk4d4math@gmail.com>

api/server/server.go

@@ -1218,7 +1218,7 @@ func ServeFd(addr string, handle http.Handler) error {
 		}()
 	}
 
-	for i := 0; i < len(ls); i += 1 {
+	for i := 0; i < len(ls); i++ {
 		err := <-chErrors
 		if err != nil {
 			return err
@@ -1366,7 +1366,7 @@ func ServeApi(job *engine.Job) engine.Status {
 		}()
 	}
 
-	for i := 0; i < len(protoAddrs); i += 1 {
+	for i := 0; i < len(protoAddrs); i++ {
 		err := <-chErrors
 		if err != nil {
 			return job.Error(err)

daemon/graphdriver/devmapper/deviceset.go

@@ -832,7 +832,7 @@ func (devices *DeviceSet) waitRemove(devname string) error {
 	log.Debugf("[deviceset %s] waitRemove(%s)", devices.devicePrefix, devname)
 	defer log.Debugf("[deviceset %s] waitRemove(%s) END", devices.devicePrefix, devname)
 	i := 0
-	for ; i < 1000; i += 1 {
+	for ; i < 1000; i++ {
 		devinfo, err := getInfo(devname)
 		if err != nil {
 			// If there is an error we assume the device doesn't exist.
@@ -861,7 +861,7 @@ func (devices *DeviceSet) waitRemove(devname string) error {
 // or b) the 10 second timeout expires.
 func (devices *DeviceSet) waitClose(info *DevInfo) error {
 	i := 0
-	for ; i < 1000; i += 1 {
+	for ; i < 1000; i++ {
 		devinfo, err := getInfo(info.Name())
 		if err != nil {
 			return err

pkg/httputils/resumablerequestreader.go

@@ -46,7 +46,7 @@ func (r *resumableRequestReader) Read(p []byte) (n int, err error) {
 	}
 	if err != nil && r.failures+1 != r.maxFailures {
 		r.cleanUpResponse()
-		r.failures += 1
+		r.failures++
 		time.Sleep(5 * time.Duration(r.failures) * time.Second)
 		return 0, nil
 	} else if err != nil {