The standalone test mode output to a file name "pretty.json". To make
the test mode more versatile, output to stdout instead. The user can
then decide how to use the output.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: David Plowman <david.plowman@raspberrypi.com>
Tested-by: David Plowman <david.plowman@raspberrypi.com>