channel->wq,
                            (mbo = most_get_mbo(channel->iface,
                                                channel->channel_id)) ||
-                           (channel->dev == NULL)))
+                           (!channel->dev)))
                        return -ERESTARTSYS;
        }
 
                goto start_copy;
        }
        while ((0 == kfifo_out(&channel->fifo, &mbo, 1))
-              && (channel->dev != NULL)) {
+              && (channel->dev)) {
                if (filp->f_flags & O_NONBLOCK)
                        return -EAGAIN;
                if (wait_event_interruptible(channel->wq,
                                             (!kfifo_is_empty(&channel->fifo) ||
-                                             (channel->dev == NULL))))
+                                             (!channel->dev))))
                        return -ERESTARTSYS;
        }
 
        }
 
        channel = get_channel(iface, channel_id);
-       if (channel == NULL)
+       if (!channel)
                return -ENXIO;
 
        mutex_lock(&channel->io_mutex);
                return -EINVAL;
 
        channel = get_channel(mbo->ifp, mbo->hdm_channel_id);
-       if (channel == NULL)
+       if (!channel)
                return -ENXIO;
 
        kfifo_in(&channel->fifo, &mbo, 1);
        }
 
        channel = get_channel(iface, channel_id);
-       if (channel == NULL)
+       if (!channel)
                return -ENXIO;
        wake_up_interruptible(&channel->wq);
        return 0;