crush: fix tree node weight lookup

Fix the node weight lookup for tree buckets by using a correct accessor.

Reflects ceph.git commit d287ade5bcbdca82a3aef145b92924cf1e856733.

Reviewed-by: Alex Elder <elder@inktank.com>
Signed-off-by: Sage Weil <sage@inktank.com>
2 files changed