LU-2194 tests: add debugging to recovery-small/19

Add error messages to 19a and 19b

Signed-off-by: Nathaniel Clark <nathaniel.l.clark@intel.com>
Change-Id: Ief35c063734654c5a6f3dab0d283c4b7a32706e8
Reviewed-on: http://review.whamcloud.com/5141
Reviewed-by: Li Wei <wei.g.li@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>