media: ispstat: use %p to print the address of a buffer

Instead of converting to int, use %p. That prevents this
warning:
	drivers/media/platform/omap3isp/ispstat.c:451 isp_stat_bufs_alloc() warn: argument 7 to %08lx specifier is cast from pointer

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>