staging: solo6010: fix signess bug

video_nr is unsigned, so check video_nr >= 0 doesn't make sense.
The only "negative" value may be -1, so explicitly check for it.

Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/solo6x10/solo6010-v4l2-enc.c

@@ -1497,7 +1497,7 @@ static struct solo_enc_dev *solo_enc_alloc(struct solo6010_dev *solo_dev, u8 ch)
 		 "%s-enc (%i/%i)", SOLO6010_NAME, solo_dev->vfd->num,
 		 solo_enc->vfd->num);
 
-	if (video_nr >= 0)
+	if (video_nr != -1)
 		video_nr++;
 
 	spin_lock_init(&solo_enc->lock);

drivers/staging/solo6x10/solo6010-v4l2.c

@@ -825,7 +825,7 @@ int solo_v4l2_init(struct solo6010_dev *solo_dev)
 	snprintf(solo_dev->vfd->name, sizeof(solo_dev->vfd->name), "%s (%i)",
 		 SOLO6010_NAME, solo_dev->vfd->num);
 
-	if (video_nr >= 0)
+	if (video_nr != -1)
 		video_nr++;
 
 	dev_info(&solo_dev->pdev->dev, "Display as /dev/video%d with "