modernizes for loop in cmd/, internal/ (#21309)

internal/s3select/csv/reader.go

@@ -230,7 +230,7 @@ func (r *Reader) startReaders(newReader func(io.Reader) *csv.Reader) error {
 	}()
 
 	// Start parsers
-	for i := 0; i < runtime.GOMAXPROCS(0); i++ {
+	for range runtime.GOMAXPROCS(0) {
 		go func() {
 			for in := range r.input {
 				if len(in.input) == 0 {

internal/s3select/json/preader.go

@@ -173,7 +173,7 @@ func (r *PReader) startReaders() {
 	}()
 
 	// Start parsers
-	for i := 0; i < runtime.GOMAXPROCS(0); i++ {
+	for range runtime.GOMAXPROCS(0) {
 		go func() {
 			for in := range r.input {
 				if len(in.input) == 0 {

internal/s3select/jstream/decoder.go

@@ -332,7 +332,7 @@ func (d *Decoder) u4() rune {
 	// logic taken from:
 	// github.com/buger/jsonparser/blob/master/escape.go#L20
 	var h [4]int
-	for i := 0; i < 4; i++ {
+	for i := range 4 {
 		c := d.next()
 		switch {
 		case c >= '0' && c <= '9':