LU-988 ost: add debugging for inode timestamps

LU-988 ost: add debugging for inode timestamps

Intermittent test failures for sanity.sh test_39j are showing the
inode timestamps going backward. Add internal debugging to track the
LVB timestamps to see where the old timestamps are coming from, to
determine if this is a problem with the VM environment being used for
testing, or if it is a genuine problem in the Lustre code.

Signed-off-by: Bobi Jam <bobijam@whamcloud.com>
Change-Id: I590d8b28b7a37010af6a43d329917022b840d074
Reviewed-on: http://review.whamcloud.com/3069
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Lai Siyao <laisiyao@whamcloud.com>
Reviewed-by: Fan Yong <yong.fan@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>