storage: stop using deprecated io/ioutil

This replaces deprecated ioutil variables and functions as follows:

* ioutil.ReadDir -> os.ReadDir
* ioutil.ReadFile -> os.ReadFile
* ioutil.TempDir -> os.MkdirTemp
* ioutil.TempFile -> os.CreateTemp
* ioutil.WriteFile -> os.WriteFile

The ReadDir conversion involves an API change, the replacement
function returns a slice of fs.DirEntry instead of fs.FileInfo.
Where appropriate, the surrounding code has been adjusted; mostly,
that means using DirEntry.Type() instead of FileInfo.Mode().
Applying this change to the IoUtil interface would mean changing its
API, so this is left for later.

Signed-off-by: Stephen Kitt <skitt@redhat.com>

pkg/volume/util/volumepathhandler/volume_path_handler_linux.go

@@ -22,7 +22,6 @@ package volumepathhandler
 import (
 	"errors"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -133,7 +132,7 @@ func getLoopDeviceFromSysfs(path string) (string, error) {
 		backingFile := fmt.Sprintf("%s/loop/backing_file", device)
 
 		// The contents of this file is the absolute path of "path".
-		data, err := ioutil.ReadFile(backingFile)
+		data, err := os.ReadFile(backingFile)
 		if err != nil {
 			continue
 		}