V4L/DVB (10934): zoran: replace functions names in strings with __func__

It reduces the size of the driver over all, and the function names in
strings need to be manually kept up to date while __func__ doesn't.

Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>