V4L/DVB (4367): Videodev: Handle class_device related errors

Add proper error checking and roll-back for failure of
class_device_create_file() in videodev.c.  Print error messages and
unroll partially created sysfs entries.
Also, failure of class_device_register() in video_register_device() is
handled correctly.  It was failing to de-allocate the minor number.  This
must be done in video_register_device(), since the caller has no way of
knowing if failure occurred before or after the class device was
registered.
Also added an error message if video_register_device() is called with
an unknown type, which should never happen.
Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

drivers/media/video/videodev.c

@@ -1538,6 +1538,8 @@ int video_register_device(struct video_device *vfd, int type, int nr)
 			name_base = "radio";
 			break;
 		default:
+			printk(KERN_ERR "%s called with unknown type: %d\n",
+			       __FUNCTION__, type);
 			return -1;
 	}
 
@@ -1592,6 +1594,15 @@ int video_register_device(struct video_device *vfd, int type, int nr)
 		       "http://lwn.net/Articles/36850/\n", vfd->name);
 #endif
 	return 0;
+
+fail_classdev:
+	class_device_unregister(&vfd->class_dev);
+fail_minor:
+	mutex_lock(&videodev_lock);
+	video_device[vfd->minor] = NULL;
+	vfd->minor = -1;
+	mutex_unlock(&videodev_lock);
+	return ret;
 }
 
 /**