doc/release-notes: v0.67.3

Signed-off-by: Sage Weil <sage@inktank.com>
crushtool: do not dump core with non-unique bucket IDs

Return -EEXIST on duplicate ID
BUG FIX: crush_add_bucket() mixes error returns and IDs
  Add optional argument to return generated ID

Fixes: #6246

Signed-off-by: David Zafman <david.zafman@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Merge git://github.com/ceph/ceph