staging: lustre: clio: update file attributes after sync

This really only affects clients that are attached to lustre
server running ZFS, because zfs does not update # of blocks
until the blocks are flushed to disk.

This patch update file's blocks attribute after OST_SYNC completes.

Signed-off-by: Bobi Jam <bobijam.xu@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-4389
Reviewed-on: http://review.whamcloud.com/12915


Reviewed-by: Nathaniel Clark <nathaniel.l.clark@intel.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>