staging: lustre: dne: setdirstripe should fail if not supported

staging: lustre: dne: setdirstripe should fail if not supported

If MDS doesn't support striped directory, creating striped directory
from a userland utility such as 'lfs setdirstripe' should fail.

Signed-off-by: Lai Siyao <lai.siyao@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6661
Reviewed-on: http://review.whamcloud.com/15123
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Andreas Dilger <andreas.dilger@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>