NFS: rename nfs_client_kset to nfs_kset

stable inclusion
from stable-v5.10.198
commit ec4325e80633c61cd82605901a4fc4b3f429dba7
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I987V5

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ec4325e80633c61cd82605901a4fc4b3f429dba7



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[ Upstream commit 8b18a2ed ]

Be brief and match the subsystem name.  There's no need to distinguish this
kset variable from the server.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Stable-dep-of: 956fd46f ("NFSv4: Fix a state manager thread deadlock regression")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>