SUNRPC: fewer conditionals in the format_ip_address routines

Clean up: have the set up routines explicitly pass the strings to be used
for the transport name and NETID.  This removes a number of conditionals
and dependencies on rpc_xprt.prot, which is overloaded.

Tighten up type checking on the address_strings array while we're at it.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h
index 51a3381..5a13da2 100644
--- a/include/linux/sunrpc/clnt.h
+++ b/include/linux/sunrpc/clnt.h
@@ -143,7 +143,7 @@
 size_t		rpc_max_payload(struct rpc_clnt *);
 void		rpc_force_rebind(struct rpc_clnt *);
 size_t		rpc_peeraddr(struct rpc_clnt *, struct sockaddr *, size_t);
-char *		rpc_peeraddr2str(struct rpc_clnt *, enum rpc_display_format_t);
+const char	*rpc_peeraddr2str(struct rpc_clnt *, enum rpc_display_format_t);
 
 #endif /* __KERNEL__ */
 #endif /* _LINUX_SUNRPC_CLNT_H */