staging: lustre: lov: Get the correct address of lmm_objects

The introduction of lmm_layout_gen makes the assumption that
lmm_objects is present after lmm_stripe_count incorrect.
Fixed this to get the correct address of lmm_objects when lmmk is cast
to lov_mds_md_v1.

Signed-off-by: Swapnil Pimpale <spimpale@ddn.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-3162
Reviewed-on: http://review.whamcloud.com/7258


Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>