tipc: remove redundant assignment to ret, simplify code

Variable err is being assigned a zero value and it is never read
afterwards in either the break path or continue path, the assignment
is redundant and can be removed. With it removed, the if statement
can also be simplified.

Cleans up clang scan warning:
net/tipc/socket.c:3570:5: warning: Value stored to 'err' is never
read [deadcode.DeadStores]
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20240411091704.306752-1-colin.i.king@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

net/tipc/socket.c

@@ -3565,11 +3565,8 @@ int tipc_nl_sk_walk(struct sk_buff *skb, struct netlink_callback *cb,
 	rhashtable_walk_start(iter);
 	while ((tsk = rhashtable_walk_next(iter)) != NULL) {
 		if (IS_ERR(tsk)) {
-			err = PTR_ERR(tsk);
-			if (err == -EAGAIN) {
-				err = 0;
+			if (PTR_ERR(tsk) == -EAGAIN)
 				continue;
-			}
 			break;
 		}