[media] v4l2-device: fix a macro definition

v4l2_device_unregister_subdev() wrongly uses "arg..." instead of "## arg"
in its body. Fix it.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/include/media/v4l2-device.h b/include/media/v4l2-device.h
index bd102cf..d61febf 100644
--- a/include/media/v4l2-device.h
+++ b/include/media/v4l2-device.h
@@ -163,7 +163,7 @@
 ({									\
 	struct v4l2_subdev *__sd;					\
 	__v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, cond, o,	\
-						f, args...);		\
+						f , ##args);		\
 })
 
 /* Call the specified callback for all subdevs matching grp_id (if 0, then