tipc: Fix end of loop tests for list_for_each_entry()

These tests are supposed to check if the loop exited via a break or not.
However the tests are wrong because if we did not exit via a break then
"p" is not a valid pointer.  In that case, it's the equivalent of
"if (*(u32 *)sr == *last_key) {".  That's going to work most of the time,
but there is a potential for those to be equal.

Fixes: 1593123 ("tipc: add name table dump to new netlink api")
Fixes: 1a1a143 ("tipc: add publication dump to new netlink api")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: Dan Carpenter

net/tipc/name_table.c

@@ -967,7 +967,7 @@ static int __tipc_nl_add_nametable_publ(struct tipc_nl_msg *msg,
 		list_for_each_entry(p, &sr->all_publ, all_publ)
 			if (p->key == *last_key)
 				break;
-		if (p->key != *last_key)
+		if (list_entry_is_head(p, &sr->all_publ, all_publ))
 			return -EPIPE;
 	} else {
 		p = list_first_entry(&sr->all_publ,

net/tipc/socket.c

@@ -3749,7 +3749,7 @@ static int __tipc_nl_list_sk_publ(struct sk_buff *skb,
 			if (p->key == *last_publ)
 				break;
 		}
-		if (p->key != *last_publ) {
+		if (list_entry_is_head(p, &tsk->publications, binding_sock)) {
 			/* We never set seq or call nl_dump_check_consistent()
 			 * this means that setting prev_seq here will cause the
 			 * consistence check to fail in the netlink callback