eulerfs: add super_operations and module_init/exit

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I40JRR


CVE: NA

--------------------------------------

Implement super_operations and module_init/exit interfaces.

Signed-off-by: Mingkai Dong <dongmingkai1@huawei.com>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>