Move C labels to start-of-line

Move C labels to start-of-line

Also mark the corresponding lint test stable.

Change-Id: Ib7c9ed88c5254bf56e68c01cdbd5ab91cd7bfc2f
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/772
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>