Replace log lines with the prefix formatter '%s: ..' and pass
'__func__' to the printers so that errors are prefixed with the
function from which they originated.

BUG=b:154285774
BRANCH=none
TEST=build success

Change-Id: If3205d8e453cfcd37f725b4fd135fe1221c913c0
Signed-off-by: Shiyu Sun <sshiyu@chromium.org>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/40901


Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>