net: mctp: avoid confusion over local/peer dest/source addresses

We have a double-swap of local and peer addresses in
mctp_alloc_local_tag; the arguments in both call sites are swapped, but
there is also a swap in the implementation of alloc_local_tag. This is
opaque because we're using source/dest address references, which don't
match the local/peer semantics.

Avoid this confusion by naming the arguments as 'local' and 'peer', and
remove the double swap. The calling order now matches mctp_key_alloc.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

include/net/mctp.h

@@ -87,7 +87,7 @@ struct mctp_sock {
 };
 
 /* Key for matching incoming packets to sockets or reassembly contexts.
- * Packets are matched on (src,dest,tag).
+ * Packets are matched on (peer EID, local EID, tag).
  *
  * Lifetime / locking requirements:
  *
@@ -254,7 +254,7 @@ int mctp_local_output(struct sock *sk, struct mctp_route *rt,
 
 void mctp_key_unref(struct mctp_sk_key *key);
 struct mctp_sk_key *mctp_alloc_local_tag(struct mctp_sock *msk,
-					 mctp_eid_t daddr, mctp_eid_t saddr,
+					 mctp_eid_t local, mctp_eid_t peer,
 					 bool manual, u8 *tagp);
 
 /* routing <--> device interface */