Merge branch 'md-next' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/song...

Pull MD updates from Song:

"The major changes are:

- REQ_NOWAIT support, by Vishal Verma
- raid6 benchmark optimization, by Dirk Müller
- Fix for acct bioset, by Xiao Ni
- Clean up max_queued_requests, by Mariusz Tkaczyk
- PREEMPT_RT optimization, by Davidlohr Bueso
- Use default_groups in kobj_type, by Greg Kroah-Hartman"

* 'md-next' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/song/md:
  md: use default_groups in kobj_type
  md: Move alloc/free acct bioset in to personality
  lib/raid6: Use strict priority ranking for pq gen() benchmarking
  lib/raid6: skip benchmark of non-chosen xor_syndrome functions
  md: fix spelling of "its"
  md: raid456 add nowait support
  md: raid10 add nowait support
  md: raid1 add nowait support
  md: add support for REQ_NOWAIT
  md: drop queue limitation for RAID1 and RAID10
  md/raid5: play nice with PREEMPT_RT