LU-3909 tests: sanity test 129 fix

LU-3909 tests: sanity test 129 fix

Patch from LU-2479 changed max dir size limit behaviour. Before the
patch last block of a directory which reached its limit was mostly
empty so that creation of new file after limit cancelation caused no
dir size grow. With the patch last block of limited directory gets
full when limit is reached. Therefore dir size increases on file
creation after limit cancellation.
The patch makes sanity test_129 to distinguish these cases.

This patch is back-ported from the following one:
Lustre-commit: 5cb9ac9c09f25234babc239ed949d85cd8489bef
Lustre-change: http://review.whamcloud.com/8143

Test-Parameters: envdefinitions=SLOW=yes,ENABLE_QUOTA=yes,ONLY=129 \
ossjob=lustre-b2_4 mdsjob=lustre-b2_4 ossbuildno=70 mdsbuildno=70 \
testlist=sanity

Xyratex-bug-id: MRP-1444

Signed-off-by: Vladmir Saveliev <vladimir_saveliev@xyratex.com>
Signed-off-by: Jian Yu <jian.yu@intel.com>
Change-Id: I691d7bac3dffe4eea98085ef2f9be3736e970869
Reviewed-on: http://review.whamcloud.com/8727
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>