i915: Fix format string warnings on x86-64.

	struct drm_gem_object *obj = ptr;

	struct drm_gem_name_info_data   *nid = data;

	DRM_INFO("name %d size %d\n", obj->name, obj->size);

	DRM_INFO("name %d size %zd\n", obj->name, obj->size);

	if (nid->eof)

		return 0;

	nid->len += sprintf(&nid->buf[nid->len],

			    "%6d%9d%8d%9d\n",

			    "%6d %8zd %7d %8d\n",

			    obj->name, obj->size,

			    atomic_read(&obj->handlecount.refcount),

			    atomic_read(&obj->refcount.refcount));