ubusd_monitor: alloc & free the buffer outside of the loop

Should save a few cycles, since the data that's
being changed is only the seq number.
And the `ub` is always created as shared.

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>

ubusd_monitor.c

@@ -72,13 +72,15 @@ ubusd_monitor_message(struct ubus_client *cl, struct ubus_msg_buf *ub, bool send
 	blob_put_int8(&mb, UBUS_MONITOR_SEND, send);
 	blob_put(&mb, UBUS_MONITOR_DATA, blob_data(ub->data), blob_len(ub->data));
 
+	ub = ubus_msg_new(mb.head, blob_raw_len(mb.head), true);
+	ub->hdr.type = UBUS_MSG_MONITOR;
+
 	list_for_each_entry(m, &monitors, list) {
-		ub = ubus_msg_new(mb.head, blob_raw_len(mb.head), true);
-		ub->hdr.type = UBUS_MSG_MONITOR;
 		ub->hdr.seq = ++m->seq;
 		ubus_msg_send(m->cl, ub);
-		ubus_msg_free(ub);
 	}
+
+	ubus_msg_free(ub);
 }
 
 static int