NFS: search for client session id in proper network namespace

Network namespace is taken from request transport and passed as a part of
cb_process_state structure.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/callback.h b/fs/nfs/callback.h
index c89d3b9..197e0d3 100644
--- a/fs/nfs/callback.h
+++ b/fs/nfs/callback.h
@@ -39,6 +39,7 @@
 	__be32			drc_status;
 	struct nfs_client	*clp;
 	int			slotid;
+	struct net		*net;
 };
 
 struct cb_compound_hdr_arg {