V4L/DVB (6285): Remove pointless kmalloc() return value cast in Zoran PCI controller driver

No need to cast the void pointer returned by kmalloc() in
drivers/media/video/zoran_driver.c::v4l_fbuffer_alloc().

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>