media: cec-adap: add '0x' prefix when printing status

It's not clear if the transmit status that is printed when debugging
is enabled is hex or decimal. Add 0x prefix to make this explicit.

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