[media] cec-adap: on reply, restore the tx_status value from the transmit

When a reply to an earlier transmit is received, the tx_status of that
transmit needs to be restored. Otherwise the status that the transmit
was successful would be lost.

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