The blk_cleanup_queue does not necesserily destroy the queue. When we
destroy the corresponding ub_dev, it may leave the queue spinlock pointer
dangling.

This patch moves spinlocks from ub_dev to static memory. The locking
scheme is not changed. These spinlocks are still separate from the ub_lock.
Signed-off-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>