libceph: init osd->o_node in create_osd()

The red-black node node in the ceph osd structure is not initialized
in create_osd().  Because this node can be the subject of a
RB_EMPTY_NODE() call later on, we should ensure the node is
initialized properly for that.  Add a call to RB_CLEAR_NODE()
initialize it.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
(cherry picked from commit f407731d12214e7686819018f3a1e9d7b6f83a02)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 37a9f1e..0b3fbdd 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -645,6 +645,7 @@
 	atomic_set(&osd->o_ref, 1);
 	osd->o_osdc = osdc;
 	osd->o_osd = onum;
+	RB_CLEAR_NODE(&osd->o_node);
 	INIT_LIST_HEAD(&osd->o_requests);
 	INIT_LIST_HEAD(&osd->o_linger_requests);
 	INIT_LIST_HEAD(&osd->o_osd_lru);