LU-7870 osd-zfs: Build against SPL/ZFS 0.6.5.6

LU-7870 osd-zfs: Build against SPL/ZFS 0.6.5.6

Build against SPL/ZFS 0.6.5.6.

Fix issue with rpm's debugedit, where it can't account for path
canonicalization causes the path to shrink by only one characater.  So
a trailing slash will cause it choke.

ZFS Changelogs since 0.6.4.3:
https://github.com/zfsonlinux/zfs/releases/tag/zfs-0.6.5.6
https://github.com/zfsonlinux/zfs/releases/tag/zfs-0.6.5.5
https://github.com/zfsonlinux/zfs/releases/tag/zfs-0.6.5.4
https://github.com/zfsonlinux/zfs/releases/tag/zfs-0.6.5.3
https://github.com/zfsonlinux/zfs/releases/tag/zfs-0.6.5.2
https://github.com/zfsonlinux/zfs/releases/tag/zfs-0.6.5.1
https://github.com/zfsonlinux/zfs/releases/tag/zfs-0.6.5

Signed-off-by: Nathaniel Clark <nathaniel.l.clark@intel.com>
Change-Id: I26569a038df605b7b6a37e2806d477029d68fca0
Reviewed-on: http://review.whamcloud.com/18920
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Christopher J. Morrone <morrone2@llnl.gov>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>