[media] media: s5p-cec: Fixed spelling mistake

Fixed spelling mistake of "successfully"

Signed-off-by: Rene Hickersberger <renehickersberger@gmx.net>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>