Support for XFS reflink clone was added in:

  commit 8ed874b3
  Author: Julio Faracco <jcfaracco@gmail.com>
  Date:   Fri Jul 6 10:43:01 2018 -0300

    storage: Rename btrfsCloneFile to support other filesystems.

  commit 2e11298f
  Author: Julio Faracco <jcfaracco@gmail.com>
  Date:   Fri Jul 6 10:43:00 2018 -0300

    configure: Adding XFS library/headers check.

But these patches missed that the xfs/xfs.h header is not installed
unless you have xfsprogs-devel present.
Reviewed-by: NAndrea Bolognani <abologna@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>