media: ddbridge: fix resources cleanup for CI hardware

Do kfree() on port->en->data instead of port->en. port->en only holds a
ptr to a struct dvb_ca_en50221, which is a member either of a memalloc'ed
struct ddb_ci (DuoFlex CI, Octopus CI Duo) or a struct cxd (CXD2099AR
based Single Flex, allocated by the cxd2099 driver). port->en.data
though holds the ptr to the allocated memory, which must rather be
kfree()'d. Change this accordingly.

Cc: Ralph Metzler <rjkm@metzlerbros.de>
Signed-off-by: Daniel Scheller <d.scheller@gmx.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>