scsi: smartpqi: Correct request leakage during reset operations

While failing queued I/Os in TMF path, there was a request leak and hence
stale entries in request pool with ref count being non-zero. In shutdown
path we have a BUG_ON to catch stuck I/O either in firmware or in the
driver. The stale requests caused a system crash. The I/O request pool
leakage also lead to a significant performance drop.

Link: https://lore.kernel.org/r/161549370379.25025.12793264112620796062.stgit@brunhildaReviewed-by: Scott Teel <scott.teel@microchip.com>
Reviewed-by: Scott Benesh <scott.benesh@microchip.com>
Reviewed-by: Kevin Barnett <kevin.barnett@microchip.com>
Signed-off-by: Murthy Bhat <Murthy.Bhat@microchip.com>
Signed-off-by: Don Brace <don.brace@microchip.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/smartpqi/smartpqi_init.c

@@ -5489,6 +5489,8 @@ static void pqi_fail_io_queued_for_device(struct pqi_ctrl_info *ctrl_info,
 
 				list_del(&io_request->request_list_entry);
 				set_host_byte(scmd, DID_RESET);
+				pqi_free_io_request(io_request);
+				scsi_dma_unmap(scmd);
 				pqi_scsi_done(scmd);
 			}
 
@@ -5525,6 +5527,8 @@ static void pqi_fail_io_queued_for_all_devices(struct pqi_ctrl_info *ctrl_info)
 
 				list_del(&io_request->request_list_entry);
 				set_host_byte(scmd, DID_RESET);
+				pqi_free_io_request(io_request);
+				scsi_dma_unmap(scmd);
 				pqi_scsi_done(scmd);
 			}