V4L/DVB (3568c): zoran: Init cleanups

Cleanups to the zr36057 initialization:
* Drop intermediate local variables.
* Single error path.
Also drop a needless cast on kfree.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>