SUNRPC: Make address format buffers more generic

For now we will assume that all transports will use the address format
buffers in the rpc_xprt struct to store their addresses.  Change
rpc_peer2str() to be a generic routine to handle this, and get rid of the
print_address() op in the rpc_xprt_ops vector.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 7d65e19..aba528b 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -594,7 +594,11 @@
 char *rpc_peeraddr2str(struct rpc_clnt *clnt, enum rpc_display_format_t format)
 {
 	struct rpc_xprt *xprt = clnt->cl_xprt;
-	return xprt->ops->print_addr(xprt, format);
+
+	if (xprt->address_strings[format] != NULL)
+		return xprt->address_strings[format];
+	else
+		return "unprintable";
 }
 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);