LU-3584 osd-zfs: error check dmu_tx_hold_sa

Add extra error checking around call to dmu_tx_hold_sa to ensure that
it succeeds.

Update lbuild target to include necessary zfs fixes (update to version
0.6.2)

Test-Parameters: testlist=racer mdsfilesystemtype=zfs  mdtfilesystemtype=zfs ostfilesystemtype=zfs
Signed-off-by: Nathaniel Clark <nathaniel.l.clark@intel.com>
Change-Id: Id9dd9aed5a50a3b6febdddcbcc0d238229bb031f
Reviewed-on: http://review.whamcloud.com/7090
Reviewed-by: Li Wei <wei.g.li@intel.com>
Tested-by: Hudson
Reviewed-by: Mike Pershin <mike.pershin@intel.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
LU-3938 osd-zfs: Account for ZAP when shrinking an xattr

When an xattr is too big for SA it is put in the ZAP, if it is
replaced with one that fits in SA, the one in ZAP should be removed,
otherwise the object will end up with two xattrs with the same name,
and everything gets confused.

Signed-off-by: Nathaniel Clark <nathaniel.l.clark@intel.com>
Change-Id: I5d33b9e505c751ec01811217377656171553659d
Reviewed-on: http://review.whamcloud.com/7671
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>