svcrdma: Clean up svc_rdma_get_inv_rkey()

 * Invalidate, and responder chooses one rkey to invalidate.

 *

 * Find a candidate rkey to invalidate when sending a reply.  Picks the

 * first rkey it finds in the chunks lists.

 * first R_key it finds in the chunk lists.

 *

 * Returns zero if RPC's chunk lists are empty.

 */

static u32 svc_rdma_get_inv_rkey(struct rpcrdma_msg *rdma_argp,

				 struct rpcrdma_write_array *wr_ary,

				 struct rpcrdma_write_array *rp_ary)

static u32 svc_rdma_get_inv_rkey(__be32 *rdma_argp,

				 __be32 *wr_lst, __be32 *rp_ch)

{

	struct rpcrdma_read_chunk *rd_ary;

	struct rpcrdma_segment *arg_ch;

	rd_ary = (struct rpcrdma_read_chunk *)&rdma_argp->rm_body.rm_chunks[0];

	if (rd_ary->rc_discrim != xdr_zero)

		return be32_to_cpu(rd_ary->rc_target.rs_handle);

	if (wr_ary && be32_to_cpu(wr_ary->wc_nchunks)) {

		arg_ch = &wr_ary->wc_array[0].wc_target;

		return be32_to_cpu(arg_ch->rs_handle);

	}

	if (rp_ary && be32_to_cpu(rp_ary->wc_nchunks)) {

		arg_ch = &rp_ary->wc_array[0].wc_target;

		return be32_to_cpu(arg_ch->rs_handle);

	}

	__be32 *p;

	p = rdma_argp + rpcrdma_fixed_maxsz;

	if (*p != xdr_zero)

		p += 2;

	else if (wr_lst && be32_to_cpup(wr_lst + 1))

		p = wr_lst + 2;

	else if (rp_ch && be32_to_cpup(rp_ch + 1))

		p = rp_ch + 2;

	else

		return 0;

	return be32_to_cpup(p);

}

static int svc_rdma_dma_map_page(struct svcxprt_rdma *rdma,

	inv_rkey = 0;

	if (rdma->sc_snd_w_inv)

		inv_rkey = svc_rdma_get_inv_rkey(rdma_argp, wr_ary, rp_ary);

		inv_rkey = svc_rdma_get_inv_rkey(&rdma_argp->rm_xid,

						 (__be32 *)wr_ary,

						 (__be32 *)rp_ary);

	/* Build an req vec for the XDR */

	vec = svc_rdma_get_req_map(rdma);