Merge tag 'xfs-4.16-merge-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Merge tag 'xfs-4.16-merge-5' of git://git./fs/xfs/xfs-linux

Pull more xfs updates from Darrick Wong:
 "As promised, here's a (much smaller) second pull request for the
  second week of the merge cycle. This time around we have a couple
  patches shutting off unsupported fs configurations, and a couple of
  cleanups.

  Last, we turn off EXPERIMENTAL for the reverse mapping btree, since
  the primary downstream user of that information (online fsck) is now
  upstream and I haven't seen any major failures in a few kernel
  releases.

  Summary:

   - Print scrub build status in the xfs build info.

   - Explicitly call out the remaining two scenarios where we don't
     support reflink and never have.

   - Remove EXPERIMENTAL tag from reverse mapping btree!"

* tag 'xfs-4.16-merge-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: remove experimental tag for reverse mapping
  xfs: don't allow reflink + realtime filesystems
  xfs: don't allow DAX on reflink filesystems
  xfs: add scrub to XFS_BUILD_OPTIONS
  xfs: fix u32 type usage in sb validation function