staging: lustre: Fix sparse endianness warnings cast to restricted __le64 and __le32

The struct lu_dirpage elements in lustre_idl.h file are modified to
__le64 and __le32 types since the  elements are always converted from
litte endian to processor native format in mdc_request.c file.

Following warnings are removed by this fix.

drivers/staging/lustre/lustre/mdc/mdc_request.c:958:42: warning: cast to restricted __le64
drivers/staging/lustre/lustre/mdc/mdc_request.c:959:42: warning: cast to restricted __le64
drivers/staging/lustre/lustre/mdc/mdc_request.c:962:42: warning: cast to restricted __le64
drivers/staging/lustre/lustre/mdc/mdc_request.c:963:42: warning: cast to restricted __le64
drivers/staging/lustre/lustre/mdc/mdc_request.c:985:50: warning: cast to restricted __le32
drivers/staging/lustre/lustre/mdc/mdc_request.c:1193:24: warning: cast to restricted __le64
drivers/staging/lustre/lustre/mdc/mdc_request.c:1328:25: warning: cast to restricted __le64
drivers/staging/lustre/lustre/mdc/mdc_request.c:1329:23: warning: cast to restricted __le64
drivers/staging/lustre/lustre/mdc/mdc_request.c:1332:25: warning: cast to restricted __le64
drivers/staging/lustre/lustre/mdc/mdc_request.c:1333:23: warning: cast to restricted __le64

Signed-off-by: Skanda Guruanand <skanda.kashyap@gmail.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>