Remove lint warning

validators.go

@@ -109,7 +109,7 @@ func loadStringSetFromFile(path string) (stringSet, error) {
 	if err != nil {
 		return stringSet{}, err
 	}
-	defer f.Close()
+	defer f.Close() // nolint: errcheck
 
 	var list []string
 	scanner := bufio.NewScanner(f)