Merge tag 'md-6.9-20240216' of https://git.kernel.org/pub/scm/linux/kernel/git/song...

Pull MD changes from Song:

"1. Cleanup redundant checks, by Yu Kuai.
 2. Remove deprecated headers, by Marc Zyngier and Song Liu.
 3. Concurrency fixes, by Li Lingfeng.
 4. Memory leak fix, by Li Nan."

* tag 'md-6.9-20240216' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md:
  md: fix kmemleak of rdev->serial
  md/multipath: Remove md-multipath.h
  md/linear: Get rid of md-linear.h
  md: use RCU lock to protect traversal in md_spares_need_change()
  md: get rdev->mddev with READ_ONCE()
  md: remove redundant md_wakeup_thread()
  md: remove redundant check of 'mddev->sync_thread'