hisi_acc_vfio_pci: Fixes error return code issue

During the process of compatibility and matching of live migration
device information, if the isolation status of the two devices is
inconsistent, the live migration needs to be exited.

The current driver does not return the error code correctly and
needs to be fixed.
Reviewed-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Longfang Liu <liulongfang@huawei.com>
Link: https://lore.kernel.org/r/20220926093332.28824-2-liulongfang@huawei.comSigned-off-by: Alex Williamson <alex.williamson@redhat.com>

drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c

@@ -397,7 +397,7 @@ static int vf_qm_check_match(struct hisi_acc_vf_core_device *hisi_acc_vdev,
 
 	if (vf_data->que_iso_cfg != que_iso_state) {
 		dev_err(dev, "failed to match isolation state\n");
-		return ret;
+		return -EINVAL;
 	}
 
 	ret = qm_write_regs(vf_qm, QM_VF_STATE, &vf_data->vf_qm_state, 1);