Install the callbacks via the state machine. No functional change.

This is the minimal fixup so we can remove the hotplug notifier mess
completely.

The real rework of this driver to use work queues is still stuck in
review/testing on the SCSI mailing list.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com>
Cc: linux-scsi@vger.kernel.org
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Chad Dupuis <chad.dupuis@qlogic.com>
Cc: QLogic-Storage-Upstream@qlogic.com
Cc: Johannes Thumshirn <jth@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20161221192111.836895753@linutronix.deSigned-off-by: Thomas Gleixner <tglx@linutronix.de>