LU-6263 lmv: fix parent FID for migration

LU-6263 lmv: fix parent FID for migration

If the migrating directory is under striped directory, it needs
to set right stripe FID for its parent.

Update migration test script (sanity test_230) to do migration
under striped dir.

Add -i to test_mkdir().

Signed-off-by: wang di <di.wang@intel.com>
Change-Id: Ic230f9b63bc21c1391e397a0d3ff689e3f0ba5dc
Reviewed-on: http://review.whamcloud.com/13817
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Fan Yong <fan.yong@intel.com>
Reviewed-by: Lai Siyao <lai.siyao@intel.com>
Tested-by: Jenkins