libceph: encode CEPH_OSD_OP_FLAG_* op flags

Encode ceph_osd_op::flags field so that it gets sent over the wire.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
diff --git a/include/linux/ceph/osd_client.h b/include/linux/ceph/osd_client.h
index fd47e87..e94f5da 100644
--- a/include/linux/ceph/osd_client.h
+++ b/include/linux/ceph/osd_client.h
@@ -76,6 +76,7 @@
 
 struct ceph_osd_req_op {
 	u16 op;           /* CEPH_OSD_OP_* */
+	u32 flags;        /* CEPH_OSD_OP_FLAG_* */
 	u32 payload_len;
 	union {
 		struct ceph_osd_data raw_data_in;