cachefiles: add output string to cachefiles_obj_[get|put]_ondemand_fd

This lets us see the correct trace output.

Fixes: c8383054 ("cachefiles: notify the user daemon when looking up cookie")
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Link: https://lore.kernel.org/r/20240522114308.2402121-2-libaokun@huaweicloud.com


Acked-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>