erofs: add support for FS_IOC_GETFSSYSFSPATH

FS_IOC_GETFSSYSFSPATH ioctl exposes /sys/fs path of a given filesystem,
potentially standarizing sysfs reporting. This patch add support for
FS_IOC_GETFSSYSFSPATH for erofs, "erofs/<dev>" will be outputted for bdev
cases, "erofs/[domain_id,]<fs_id>" will be outputted for fscache cases.

Signed-off-by: Huang Xiaojia <huangxiaojia2@huawei.com>
Link: https://lore.kernel.org/r/20240720082335.441563-1-huangxiaojia2@huawei.com


Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>