Patch 97e81f2d78f3 (Add support for metadata in barebox images)
writes the wrong length for the model tag in the barebox metadata.
Fix this to use the correct value.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>