V4L/DVB (10138): v4l2-ioctl: change to long return type to match unlocked_ioctl.

Since internal to v4l2 the ioctl prototype is the same regardless of it
being called through .ioctl or .unlocked_ioctl, we need to convert it all
to the long return type of unlocked_ioctl.

Thanks to Jean-Francois Moine for posting an initial patch for this and
thus bringing it to our attention.

Cc: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

include/media/v4l2-device.h

@@ -80,7 +80,7 @@ void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
 #define __v4l2_device_call_subdevs_until_err(dev, cond, o, f, args...)  \
 ({ 									\
 	struct v4l2_subdev *sd; 					\
-	int err = 0; 							\
+	long err = 0; 							\
 									\
 	list_for_each_entry(sd, &(dev)->subdevs, list) { 		\
 		if ((cond) && sd->ops->o && sd->ops->o->f) 		\