media: v4l: subdev: v4l2_subdev_state_get_format always returns format now

Now that v4l2_subdev_state_get_format() always returns format, don't call
alternative v4l2_subdev_get_pad_format() anymore.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>