V4L/DVB (9859): gspca - ov534: Fix frame size so we don't miss the last pixel.

The frame size is too small, so we lose the last YUYV pixel.
Fix the setup and remove the last_pixel hack.

Signed-off-by: Jim Paris <jim@jtan.com>
Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>