scsi: hpsa: Add an assert to prevent __packed reintroduction

scsi: hpsa: Add an assert to prevent __packed reintroduction

Link: https://lore.kernel.org/r/20210330071958.3788214-3-slyfox@gentoo.org
Fixes: f749d8b7a989 ("scsi: hpsa: Correct dev cmds outstanding for retried cmds")
CC: linux-ia64@vger.kernel.org
CC: storagedev@microchip.com
CC: linux-scsi@vger.kernel.org
CC: Joe Szczypek <jszczype@redhat.com>
CC: Scott Benesh <scott.benesh@microchip.com>
CC: Scott Teel <scott.teel@microchip.com>
CC: Tomas Henzl <thenzl@redhat.com>
CC: "Martin K. Petersen" <martin.petersen@oracle.com>
CC: Don Brace <don.brace@microchip.com>
Reported-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Suggested-by: Don Brace <don.brace@microchip.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>