If Hauppauge eeprom is corrupted, the driver returns tuner = 0, instead
of TUNER_ABSENT.

This makes the drivers to initialize tuner, instead of handling the
manual parameter.

Since the tuner core rejects that a tuner to have their type changed,
this breaks the manual tuner override.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>