staging/lustre/llite: issue OST_SYNC for fsync()

The last parameter @datasync of fsync() has following indication:
* if datasync=0, we'd always flush data and metadata
* if datasync=1, we'd always flush data while does not flush modifed
  metadata unless that metadata is needed in order to allow a
  subsequent data retrieval to be correctly handled. For example, a
  change to the file size would require a metadata flush.

Lustre client can not tell the difference easily, and would issue
MDS_SYNC and OST_SYNC in all cases.
Signed-off-by: NBobi Jam <bobijam.xu@intel.com>
Reviewed-on: http://review.whamcloud.com/8684
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-4388Reviewed-by: NAndreas Dilger <andreas.dilger@intel.com>
Reviewed-by: NJinshan Xiong <jinshan.xiong@intel.com>
Signed-off-by: NOleg Drokin <oleg.drokin@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/llite/file.c

@@ -2653,7 +2653,7 @@ int ll_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 	if (!err)
 		ptlrpc_req_finished(req);
 
-	if (datasync && S_ISREG(inode->i_mode)) {
+	if (S_ISREG(inode->i_mode)) {
 		struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
 
 		err = cl_sync_file_range(inode, 0, OBD_OBJECT_EOF,