The type of the variable participating in the shift operation should be an
unsigned type instead of a signed type.

Link: https://lore.kernel.org/r/20211119140208.40416-5-liangwenpeng@huawei.comSigned-off-by: NXinhao Liu <liuxinhao5@hisilicon.com>
Signed-off-by: NWenpeng Liang <liangwenpeng@huawei.com>
Signed-off-by: NJason Gunthorpe <jgg@nvidia.com>