illumos/illumos-gate@555d674d5d555d674d5dhttps://www.illumos.org/issues/10592
This is a collection of recent fixes from ZoL:
8eef997679 Error path in metaslab_load_impl() forgets to drop ms_sync_lock
928e8ad47d Introduce auxiliary metaslab histograms
425d3237ee Get rid of space_map_update() for ms_synced_length
6c926f426a Simplify log vdev removal code
21e7cf5da8 zdb -L should skip leak detection altogether
df72b8bebe Rename range_tree_verify to range_tree_verify_not_present
75058f3303 Remove unused vdev_t fields
Portions contributed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Author: Serapheim Dimitropoulos <serapheim@delphix.com>
MFC after: 4 weeks