Move scsi_remove_host call into sas_remove_host and remove it from SAS
HBA drivers, so we don't mess up the ordering. This solves an issue with
double deleting sysfs entries that was introduced by the change of sysfs
behaviour from commit bcdde7e2 ("sysfs: make __sysfs_remove_dir()
recursive").

[mkp: addressed checkpatch complaints]
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Suggested-by: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: James Bottomley <jejb@linux.vnet.ibm.com>
Cc: Jinpu Wang <jinpu.wang@profitbricks.com>
Cc: John Garry <john.garry@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jinpu Wang <jinpu.wang@profitbricks.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>