There is no reason that calls to block_unblock_all_queues() from differentAcked-by: Douglas Gilbert <dgilbert@xxxxxxxxxxxx>
context can't race with one another, so protect with the
sdebug_host_list_mutex. There's no need for a more fine-grained per shost
locking here (and we don't have a per-host lock anyway).
Also simplify some touched code in sdebug_change_qdepth().
Signed-off-by: John Garry <john.g.garry@xxxxxxxxxx>