The type of wqe length is u32 so in order to avoid overflow and shadow
casting change variable and relevant function argument to proper type.

Link: https://lore.kernel.org/r/20220307145047.3235675-1-cgxu519@mykernel.netSigned-off-by: Chengguang Xu <cgxu519@mykernel.net>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>