virtio: console: rename cvq_lock to c_ivq_lock

commit 165b1b8b upstream.

The cvq_lock was taken for the c_ivq.  Rename the lock to make that
obvious.

We'll also add a lock around the c_ovq in the next commit, so there's no
ambiguity.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Asias He <asias@redhat.com>
Reviewed-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
[bwh: Backported to 3.2:
 - Adjust context
 - Drop change to virtcons_restore()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/char/virtio_console.c

@@ -131,7 +131,7 @@ struct ports_device {
 	spinlock_t ports_lock;
 
 	/* To protect the vq operations for the control channel */
-	spinlock_t cvq_lock;
+	spinlock_t c_ivq_lock;
 
 	/* The current config space is stored here */
 	struct virtio_console_config config;
@@ -1466,23 +1466,23 @@ static void control_work_handler(struct work_struct *work)
 	portdev = container_of(work, struct ports_device, control_work);
 	vq = portdev->c_ivq;
 
-	spin_lock(&portdev->cvq_lock);
+	spin_lock(&portdev->c_ivq_lock);
 	while ((buf = virtqueue_get_buf(vq, &len))) {
-		spin_unlock(&portdev->cvq_lock);
+		spin_unlock(&portdev->c_ivq_lock);
 
 		buf->len = len;
 		buf->offset = 0;
 
 		handle_control_message(portdev, buf);
 
-		spin_lock(&portdev->cvq_lock);
+		spin_lock(&portdev->c_ivq_lock);
 		if (add_inbuf(portdev->c_ivq, buf) < 0) {
 			dev_warn(&portdev->vdev->dev,
 				 "Error adding buffer to queue\n");
 			free_buf(buf);
 		}
 	}
-	spin_unlock(&portdev->cvq_lock);
+	spin_unlock(&portdev->c_ivq_lock);
 }
 
 static void out_intr(struct virtqueue *vq)
@@ -1721,10 +1721,11 @@ static int __devinit virtcons_probe(struct virtio_device *vdev)
 	if (multiport) {
 		unsigned int nr_added_bufs;
 
-		spin_lock_init(&portdev->cvq_lock);
+		spin_lock_init(&portdev->c_ivq_lock);
 		INIT_WORK(&portdev->control_work, &control_work_handler);
 
-		nr_added_bufs = fill_queue(portdev->c_ivq, &portdev->cvq_lock);
+		nr_added_bufs = fill_queue(portdev->c_ivq,
+					   &portdev->c_ivq_lock);
 		if (!nr_added_bufs) {
 			dev_err(&vdev->dev,
 				"Error allocating buffers for control queue\n");