media: omap3isp: fix uninitialized variable use

A debug printk statement was copied incorrectly into the new
csi1 parser code and causes a warning there:

drivers/media/platform/omap3isp/isp.c: In function 'isp_probe':
include/linux/dynamic_debug.h:134:3: error: 'i' may be used uninitialized in this function [-Werror=maybe-uninitialized]

Since there is only one lane, the index is never set. This
changes the debug print to always print a zero instead,
keeping the original format of the message.

Fixes: 9211434b ("media: omap3isp: Parse CSI1 configuration from the device tree")

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>