staging: lustre: llite: fix "getdirstripe" to show stripe info

Fix "lfs getdirstripe", so it can show layout information
of striped directory

[root@testnode tests]# ../utils/lfs getdirstripe /mnt/lustre/test1
/mnt/lustre/test1
lmv_stripe_count: 2
lmv_stripe_offset: 0
mdtidx               FID[seq:oid:ver]
     0               [0x280000400:0x1:0x0]
     1               [0x2c0000400:0x1:0x0]

Signed-off-by: wang di <di.wang@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-3531
Reviewed-on: http://review.whamcloud.com/7228


Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>