libceph: init event->node in ceph_osdc_create_event()

libceph: init event->node in ceph_osdc_create_event()

The red-black node node in the ceph osd event structure is not
initialized in create_osdc_create_event().  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.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
(cherry picked from commit 3ee5234df68d253c415ba4f2db72ad250d9c21a9)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>