libceph: allow setting osd_req_op's flags

Signed-off-by: Yan, Zheng <zyan@redhat.com>
Reviewed-by: Alex Elder <elder@linaro.org>
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index e162bcd..feeaf3b 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -884,7 +884,8 @@
 				}
 
 				if (do_sync)
-					osd_req_op_init(req, 1, CEPH_OSD_OP_STARTSYNC);
+					osd_req_op_init(req, 1,
+							CEPH_OSD_OP_STARTSYNC, 0);
 
 				req->r_callback = writepages_finish;
 				req->r_inode = inode;