xfs: updates for 4.3-rc1

This update contains:
o large rework of EFI/EFD lifecycle handling to fix log recovery corruption
  issues, crashes and unmount hangs
o separate metadata UUID on disk to enable changing boot label UUID for v5
  filesystems
o fixes for gcc miscompilation on certain platforms and optimisation levels
o remote attribute allocation and recovery corruption fixes
o inode lockdep annotation rework to fix bugs with too many subclasses
o directory inode locking changes to prevent lockdep false positives
o a handful of minor corruption fixes
o various other small cleanups and bug fixes
Merge branch 'xfs-misc-fixes-for-4.3-4' into for-next