ZTS: Fix pool_state cleanup

The externally faulted vdev should be brought back online and have
its errors cleared before the pool is destroyed. Failure to do so
will leave a vdev with a valid active label. This vdev may then
not be used to create a new pool without the -f flag potentially
leading to subsequent test failures.

Additionally remove an unreachable log_pass from setup.ksh.

Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Kjeld Schouten <kjeld@schouten-lebbing.nl>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #9777