RDMA/rxe: Change variable and function argument to proper type

RDMA/rxe: Change variable and function argument to proper type

[ Upstream commit 7e8e611d6a0ff228577b1167335ffefb0f44d5d8 ]

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.net
Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>