staging/lustre: use ATTR_OPEN directly, remove ATTR_RAW

ATTR_RAW is unused.
No point in redefining ATTR_OPEN as ATTR_FROM_OPEN

Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>