ccan/io: replace backend_set_state with backend_wakeup()

We only use it in one place: for wakeup.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

ccan/io/backend.h

@@ -103,7 +103,7 @@ bool add_listener(struct io_listener *l);
 bool add_conn(struct io_conn *c);
 bool add_duplex(struct io_conn *c);
 void del_listener(struct io_listener *l);
-void backend_set_state(struct io_conn *conn, struct io_plan *op);
+void backend_wakeup(struct io_conn *conn);
 void backend_add_timeout(struct io_conn *conn, struct timespec ts);
 void backend_del_timeout(struct io_conn *conn);
 

ccan/io/io.c

@@ -239,7 +239,8 @@ void io_wake_(struct io_conn *conn,
 	assert(conn->state == IO_IDLE);
 	conn->next = fn;
 	conn->next_arg = arg;
-	backend_set_state(conn, to_ioplan(IO_NEXT));
+	conn->state = IO_NEXT;
+	backend_wakeup(conn);
 }
 
 static struct io_plan *do_next(struct io_conn *conn)

ccan/io/poll.c

@@ -112,7 +112,7 @@ void del_listener(struct io_listener *l)
 	del_fd(&l->fd);
 }
 
-void backend_set_state(struct io_conn *conn, struct io_plan *plan)
+static void backend_set_state(struct io_conn *conn, struct io_plan *plan)
 {
 	enum io_state state = from_ioplan(plan);
 	struct pollfd *pfd = &pollfds[conn->fd.backend_info];
@@ -138,6 +138,11 @@ void backend_set_state(struct io_conn *conn, struct io_plan *plan)
 	conn->state = state;
 }
 
+void backend_wakeup(struct io_conn *conn)
+{
+	num_next++;
+}
+
 static void accept_conn(struct io_listener *l)
 {
 	struct io_conn *c;