update_handler: fix error handling in copy_raw_image
update_handler: fix error handling in copy_raw_image

copy_raw_image always returned TRUE, even in case of an error.

Signed-off-by: Enrico Jorns <a2e5f936c390f36494e46e71bcfbe365bb1e8c49@pengutronix.de>

rauc/rauc,rauc/rauc,ejoerns/rauc,jluebbe/rauc,rauc/rauc,ejoerns/rauc,ejoerns/rauc,jluebbe/rauc,jluebbe/rauc