Give keys their own lockdep class to differentiate them from each other in case
a key of one type has to refer to a key of another type.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>