s390/vfio-ap: fix an error handling path in vfio_ap_mdev_probe_queue()

The commit in Fixes: has switch the order of a sysfs_create_group() and a
kzalloc().

It correctly removed the now useless kfree() but forgot to add a
sysfs_remove_group() in case of (unlikely) memory allocation failure.

Add it now.

Fixes: 260f3ea1 ("s390/vfio-ap: move probe and remove callbacks to vfio_ap_ops.c")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/r/d0c0a35eec4fa87cb7f3910d8ac4dc0f7dc9008a.1659283738.git.christophe.jaillet@wanadoo.frSigned-off-by: Heiko Carstens <hca@linux.ibm.com>

drivers/s390/crypto/vfio_ap_ops.c

@@ -1857,8 +1857,10 @@ int vfio_ap_mdev_probe_queue(struct ap_device *apdev)
 		return ret;
 
 	q = kzalloc(sizeof(*q), GFP_KERNEL);
-	if (!q)
-		return -ENOMEM;
+	if (!q) {
+		ret = -ENOMEM;
+		goto err_remove_group;
+	}
 
 	q->apqn = to_ap_queue(&apdev->device)->qid;
 	q->saved_isc = VFIO_AP_ISC_INVALID;
@@ -1876,6 +1878,10 @@ int vfio_ap_mdev_probe_queue(struct ap_device *apdev)
 	release_update_locks_for_mdev(matrix_mdev);
 
 	return 0;
+
+err_remove_group:
+	sysfs_remove_group(&apdev->device.kobj, &vfio_queue_attr_group);
+	return ret;
 }
 
 void vfio_ap_mdev_remove_queue(struct ap_device *apdev)