IB/mlx5: Fix leaking stack memory to userspace

mlx5_ib_create_qp_resp was never initialized and only the first 4 bytes
were written.

Fixes: 41d902cb7c32 ("RDMA/mlx5: Fix definition of mlx5_ib_create_qp_resp")
Cc: <stable@vger.kernel.org>
Acked-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
static void destroy_qp_user(struct mlx5_ib_dev *dev, struct ib_pd *pd,
			    struct mlx5_ib_qp *qp, struct mlx5_ib_qp_base *base)
{
	struct mlx5_ib_ucontext *context;

	context = to_mucontext(pd->uobject->context);
	mlx5_ib_db_unmap_user(context, &qp->db);
	if (base->ubuffer.umem)
		ib_umem_release(base->ubuffer.umem);

	/*
	 * Free only the BFREGs which are handled by the kernel.
	 * BFREGs of UARs allocated dynamically are handled by user.
	 */
	if (qp->bfregn != MLX5_IB_INVALID_BFREG)
		mlx5_ib_free_bfreg(dev, &context->bfregi, qp->bfregn);
}

static void destroy_qp_user(struct mlx5_ib_dev *dev, struct ib_pd *pd,
			    struct mlx5_ib_qp *qp, struct mlx5_ib_qp_base *base)
{
	struct mlx5_ib_ucontext *context;

	context = to_mucontext(pd->uobject->context);
	mlx5_ib_db_unmap_user(context, &qp->db);
	if (base->ubuffer.umem)
		ib_umem_release(base->ubuffer.umem);

	/*
	 * Free only the BFREGs which are handled by the kernel.
	 * BFREGs of UARs allocated dynamically are handled by user.
	 */
	if (qp->bfregn != MLX5_IB_INVALID_BFREG)
		mlx5_ib_free_bfreg(dev, &context->bfregi, qp->bfregn);
}
