sunrpc: skip portmap calls on sessions backchannel

Committing for 3.4.

(I noticed this while debugging the hang seen after applying jlayton's patches. It doesn't fix that, though.)

--b.

commit b3436278b5758647b942806c5da1c118a4e2540d

Author: J. Bruce Fields <[email protected]>
Date:   Fri Mar 23 15:25:03 2012 -0400

sunrpc: skip portmap calls on sessions backchannel

There's obviously no point to doing portmap calls over the sessions backchannel.

index 92bc518..890b03f 100644
@@ -2475,6 +2475,7 @@ static struct rpc_xprt_ops xs_tcp_ops = {
 static struct rpc_xprt_ops bc_tcp_ops = {
 	.reserve_xprt		= xprt_reserve_xprt,
 	.release_xprt		= xprt_release_xprt,
+	.rpcbind		= xs_local_rpcbind,
 	.buf_alloc		= bc_malloc,
 	.buf_free		= bc_free,
 	.send_request		= bc_send_request,