hpsa: correct handling of HBA device removal

Need to report HBA device removal faster than the
event handler polling interval.

Stop I/O to the removed disk and wait for all
I/O operations to flush before removing the device.

Reviewed-by: Scott Teel <scott.teel@microsemi.com>
Reviewed-by: Kevin Barnett <kevin.barnett@microsemi.com>
Signed-off-by: Don Brace <don.brace@microsemi.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/hpsa.h

@@ -63,6 +63,7 @@ struct hpsa_scsi_dev_t {
 	unsigned char scsi3addr[8];	/* as presented to the HW */
 	u8 physical_device : 1;
 	u8 expose_device;
+	u8 removed : 1;			/* device is marked for death */
 #define RAID_CTLR_LUNID "\0\0\0\0\0\0\0\0"
 	unsigned char device_id[16];    /* from inquiry pg. 0x83 */
 	u64 sas_address;