After the first run, the test case 'test_create_read' will always
fail because the file is exist and file's attr is 'S_IMMUTABLE',
open with 'O_RDWR' will always return -EPERM.
Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Shuah Khan <shuah@kernel.org>