accounts/keystore: rename skipKeyFile to nonKeyFile to better reveal …

…the function purpose (ethereum#17290)

accounts/keystore/file_cache.go

@@ -55,20 +55,20 @@ func (fc *fileCache) scan(keyDir string) (mapset.Set, mapset.Set, mapset.Set, er
 
 	var newLastMod time.Time
 	for _, fi := range files {
-		// Skip any non-key files from the folder
 		path := filepath.Join(keyDir, fi.Name())
-		fiInfo, err := fi.Info()
-		if err != nil {
-			log.Warn("scan get FileInfo", "err", err, "path", path)
-		}
-		if fiInfo == nil || skipKeyFile(fiInfo) {
+		// Skip any non-key files from the folder
+		if nonKeyFile(fi) {
 			log.Trace("Ignoring file on account scan", "path", path)
 			continue
 		}
 		// Gather the set of all and fresly modified files
 		all.Add(path)
 
-		modified := fiInfo.ModTime()
+		info, err := fi.Info()
+		if err != nil {
+			return nil, nil, nil, err
+		}
+		modified := info.ModTime()
 		if modified.After(fc.lastMod) {
 			mods.Add(path)
 		}
@@ -91,15 +91,14 @@ func (fc *fileCache) scan(keyDir string) (mapset.Set, mapset.Set, mapset.Set, er
 	return creates, deletes, updates, nil
 }
 
-// skipKeyFile ignores editor backups, hidden files and folders/symlinks.
-func skipKeyFile(fi os.FileInfo) bool {
+// nonKeyFile ignores editor backups, hidden files and folders/symlinks.
+func nonKeyFile(fi os.DirEntry) bool {
 	// Skip editor backups and UNIX-style hidden files.
-	name := fi.Name()
-	if strings.HasSuffix(name, "~") || strings.HasPrefix(name, ".") {
+	if strings.HasSuffix(fi.Name(), "~") || strings.HasPrefix(fi.Name(), ".") {
 		return true
 	}
 	// Skip misc special files, directories (yes, symlinks too).
-	if fi.IsDir() || fi.Mode()&os.ModeType != 0 {
+	if fi.IsDir() || !fi.Type().IsRegular() {
 		return true
 	}
 	return false