scsi: qla2xxx: Remove qla_tgt_cmd.released

Since the previous patch removed the only statement that sets
qla_tgt_cmd.released, remove the code that depends on that member variable
being set and the member variable itself.

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