Address comments

- Thanks to Markus for suggestion about simplify the logic to get
excluded file paths

test/test_images/runtime/handlers/file_access_attempt.go

@@ -70,8 +70,11 @@ func checkReadable(path string) error {
 		return err
 	}
 	readFile, err := os.OpenFile(path, os.O_RDONLY, 0)
-	defer readFile.Close()
-	return err
+	if err != nil {
+		return err
+	}
+	readFile.Close()
+	return nil
 }
 
 // checkWritable function checks whether path file or directory is writable

test/test_images/runtime/handlers/runtime.go

@@ -60,14 +60,16 @@ func excludeFilePaths(filePaths []string, excludedPaths []string) []string {
 	var paths []string
 	for _, path := range filePaths {
 		excluded := false
-		for i := len(excludedPaths) - 1; i >= 0 && !excluded; i-- {
-			excluded = path == excludedPaths[i]
+		for _, excludedPath := range excludedPaths {
+			if path == excludedPath {
+				excluded = true
+				break
+			}
 		}
 
 		if !excluded {
 			paths = append(paths, path)
 		}
 	}
-
 	return paths
 }