Fix a harmless typo replacing obj by elem in the cleanup fields.  This has
no effect but is confusing.

Link: https://lore.kernel.org/r/20220304000808.225811-6-rpearsonhpe@gmail.comSigned-off-by: NBob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: NJason Gunthorpe <jgg@nvidia.com>