Merge tag 'ovl-fixes-6.15-rc2' of ssh://gitolite.kernel.org/pub/scm/linux/kernel...

Bring in overlayfs fixes for the current cycle.

* tag 'ovl-fixes-6.15-rc2' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs:
  ovl: remove unused forward declaration
  ovl: don't allow datadir only

Link: https://lore.kernel.org/CAJfpegt-EE4RROKDXA3g5GxAYXQrWcLAL1TfTPK-%3DVmPC7U13g@mail.gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>