UPSTREAM: kernfs: dont call d_splice_alias() under kernfs node lock

The call to d_splice_alias() in kernfs_iop_lookup() doesn't depend on
any kernfs node so there's no reason to hold the kernfs node lock when
calling it.

Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Link: https://lore.kernel.org/r/162642772000.63632.10672683419693513226.stgit@web.messagingengine.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

(cherry picked from commit df6192f4)

Bug: 320903885
Bug: 219424218
Bug: 206126556
Change-Id: I5feacf76e23f9ff1840f58ebd791158f1a126b64
Signed-off-by: Suren Baghdasaryan <surenb@google.com>