Merge tag 'md-3.6-fixes' of git://neil.brown.name/md

Pull md fixes from NeilBrown:
 "2 fixes for md, tagged for -stable"

* tag 'md-3.6-fixes' of git://neil.brown.name/md:
  md/raid10: fix problem with on-stack allocation of r10bio structure.
  md: Don't truncate size at 4TB for RAID0 and Linear