scsi: qla2xxx: Unregister resources in the opposite order of the registration order

Make sure that resources are only unregistered after the users of these
resources have been unregistered. Only unregister the character device if
registration of it succeeded.

Cc: Himanshu Madhani <hmadhani@marvell.com>
Cc: Giridhar Malavali <gmalavali@marvell.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>