qla2xxx: fix kernel NULL pointer access

This patch is to fix regression added by commit id
51a07f8.

When allocating memory for new session original patch does
not assign vha to op->vha resulting into NULL pointer
access during qlt_create_sess_from_atio().

Cc: <stable@vger.kernel.org>
Signed-off-by: Himanshu Madhani <himanshu.madhani@qlogic.com>
Signed-off-by: Saurav Kashyap <saurav.kashyap@qlogic.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/scsi/qla2xxx/qla_target.c

@@ -3277,6 +3277,7 @@ static int qlt_handle_cmd_for_atio(struct scsi_qla_host *vha,
 			return -ENOMEM;
 
 		memcpy(&op->atio, atio, sizeof(*atio));
+		op->vha = vha;
 		INIT_WORK(&op->work, qlt_create_sess_from_atio);
 		queue_work(qla_tgt_wq, &op->work);
 		return 0;