loopfs: only show devices in their correct instance

Since loopfs devices belong to a loopfs instance they have no business
polluting the host's devtmpfs mount and should not propagate out of the
namespace they belong to.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
3 files changed