Added vdev_resilver_needed() check to verify VDEVs are fully
synced, so that after split the new pool will not be corrupted.
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Signed-off-by: Roman Strashkin <roman.strashkin@nexenta.com>
Closes#7865Closes#7881