LU-6826 lod: validate stripe_count and offset

LU-6826 lod: validate stripe_count and offset

Validate stripe_offset and stripe_count in lod_ah_init, so
these two values will not cause unexpected failures in the
following creation.

Add sanity.sh 300m to verify the case.

Signed-off-by: wang di <di.wang@intel.com>
Change-Id: I3d36b29079a36355eb4a8d645b70c04aa6d80a40
Reviewed-on: http://review.whamcloud.com/16130
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Lai Siyao <lai.siyao@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>