scsi: hpsa: Correct dev cmds outstanding for retried cmds

Prevent incrementing device->commands_outstanding for ioaccel command
retries that are driver initiated.  If the command goes through the retry
path, the device->commands_outstanding counter has already accounted for
the number of commands outstanding to the device.  Only commands going
through function hpsa_cmd_resolve_events decrement this counter.

 - ioaccel commands go to either HBA disks or to logical volumes comprised
   of SSDs.

The extra increment is causing device resets to hang.

 - Resets wait for all device outstanding commands to complete before
   returning.

Replace unused field abort_pending with retry_pending. This is a
maintenance driver so these changes have the least impact/risk.

Link: https://lore.kernel.org/r/161342801747.29388.13045495968308188518.stgit@brunhilda


Tested-by: Joe Szczypek <jszczype@redhat.com>
Reviewed-by: Scott Benesh <scott.benesh@microchip.com>
Reviewed-by: Scott Teel <scott.teel@microchip.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Don Brace <don.brace@microchip.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>