nfsd4: fix bind_conn_to_session xdr comment

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

fs/nfsd/nfs4xdr.c

@@ -2659,7 +2659,7 @@ static __be32 nfsd4_encode_bind_conn_to_session(struct nfsd4_compoundres *resp,
 		RESERVE_SPACE(NFS4_MAX_SESSIONID_LEN + 8);
 		WRITEMEM(bcts->sessionid.data, NFS4_MAX_SESSIONID_LEN);
 		WRITE32(bcts->dir);
-		/* XXX: ? */
+		/* Sorry, we do not yet support RDMA over 4.1: */
 		WRITE32(0);
 		ADJUST_ARGS();
 	}