V4L/DVB (11926): tuner-core: fix warning introduced when cleaning up xc5000 init routine

This patch removes some remaining dead code.  Warning showed up in Hans
Verkuil's daily report after I committed hg changeset 7f2eea75118b.

Thanks to Michael Krufky for bringing the warning to my attention.

Cc: Michael Krufky <mkrufky@kernellabs.com>
Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>