scsi: iscsi: Fix recovery and unblocking race

scsi: iscsi: Fix recovery and unblocking race

If the user sets the iscsi_eh_timer_workq/iscsi_eh workqueue's max_active
to greater than 1, the recovery_work could be running when
__iscsi_unblock_session() runs. The cancel_delayed_work() will then not
wait for the running work and we can race where we end up with the wrong
session state and scsi_device state set.

This replaces the cancel_delayed_work() with the sync version.

Link: https://lore.kernel.org/r/20220226230435.38733-2-michael.christie@oracle.com
Reviewed-by: Lee Duncan <lduncan@suse.com>
Reviewed-by: Chris Leech <cleech@redhat.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>