LU-2547 tests: EXCLUDE recovery-small/24b for ZFS

LU-2547 tests: EXCLUDE recovery-small/24b for ZFS

Exclude test because it fails in the same way as 24a and in theory
should be fixed simultaniously.

Signed-off-by: Nathaniel Clark <nathaniel.l.clark@intel.com>
Change-Id: Iea5aaddf41b5765efce22cc7e32234cb1a8e49ae
Reviewed-on: http://review.whamcloud.com/6587
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Hudson
Reviewed-by: Jian Yu <jian.yu@intel.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-on: http://review.whamcloud.com/7424