cgroup: use legacy_name for cgroup v1 disable info

mainline inclusion
from mainline-v6.7-rc1
commit 27a6c5c50c4bb0c56296f01a3142db796bb01da1
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I91BXW



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cgroup v1 or v2 or both controller names can be passed as arguments to
the 'cgroup_no_v1' kernel parameter, though most of the controller's
names are the same for both cgroup versions. This can be confusing when
both versions are used interchangeably, i.e., passing cgroup_no_v1=io

$ sudo dmesg |grep cgroup
...
cgroup: Disabling io control group subsystem in v1 mounts
cgroup: Disabled controller 'blkio'

Make it consistent across the pr_info()'s, by using ss->legacy_name, as
the subsystem name, while printing the cgroup v1 controller disabling
information in cgroup_init().

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Chen Ridong <chenridong@huawei.com>