Fix lint errors

cmd/internal/protogen/main.go

@@ -48,8 +48,8 @@ func GetRuntimeEnv(key string) (string, error) {
 	if readErr != nil {
 		return "", readErr
 	}
-	envStrings := strings.Split(string(data), "\n")
-	for _, envItem := range envStrings {
+	envStrings := strings.SplitSeq(string(data), "\n")
+	for envItem := range envStrings {
 		envItem = strings.TrimSuffix(envItem, "\r")
 		envKeyValue := strings.Split(envItem, "=")
 		if strings.EqualFold(strings.TrimSpace(envKeyValue[0]), key) {

cmd/internal/update_android_version/main.go

@@ -39,7 +39,7 @@ func main() {
 	common.Must(os.Chdir(androidPath))
 	localProps := common.Must1(os.ReadFile("version.properties"))
 	var propsList [][]string
-	for _, propLine := range strings.Split(string(localProps), "\n") {
+	for propLine := range strings.SplitSeq(string(localProps), "\n") {
 		propsList = append(propsList, strings.Split(propLine, "="))
 	}
 	var (

cmd/sing-box/cmd_geoip_export.go

@@ -61,16 +61,17 @@ func geoipExport(countryCode string) error {
 		outputFile   *os.File
 		outputWriter io.Writer
 	)
-	if flagGeoipExportOutput == "stdout" {
+	switch flagGeoipExportOutput {
+	case "stdout":
 		outputWriter = os.Stdout
-	} else if flagGeoipExportOutput == flagGeoipExportDefaultOutput {
+	case flagGeoipExportDefaultOutput:
 		outputFile, err = os.Create("geoip-" + countryCode + ".json")
 		if err != nil {
 			return err
 		}
 		defer outputFile.Close()
 		outputWriter = outputFile
-	} else {
+	default:
 		outputFile, err = os.Create(flagGeoipExportOutput)
 		if err != nil {
 			return err

cmd/sing-box/cmd_geosite_export.go

@@ -43,16 +43,17 @@ func geositeExport(category string) error {
 		outputFile   *os.File
 		outputWriter io.Writer
 	)
-	if commandGeositeExportOutput == "stdout" {
+	switch commandGeositeExportOutput {
+	case "stdout":
 		outputWriter = os.Stdout
-	} else if commandGeositeExportOutput == commandGeositeExportDefaultOutput {
+	case commandGeositeExportDefaultOutput:
 		outputFile, err = os.Create("geosite-" + category + ".json")
 		if err != nil {
 			return err
 		}
 		defer outputFile.Close()
 		outputWriter = outputFile
-	} else {
+	default:
 		outputFile, err = os.Create(commandGeositeExportOutput)
 		if err != nil {
 			return err