[media] omap3isp: resizer: Remove needless variable initializations

There's no need to initialize local variables to zero when they're
explicitly assigned another value right after. Remove the needless
initializations.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>