VT-d: fix deassign of device with RMRR

VT-d: fix deassign of device with RMRR

Ignoring a specific error code here was not meant to short circuit
deassign to _just_ the unmapping of RMRRs. This bug was previously
hidden by the bogus (potentially indefinite) looping in
pci_release_devices(), until f591755823a7 ("IOMMU/PCI: don't let domain
cleanup continue when device de-assignment failed") fixed that loop.

This is CVE-2021-28702 / XSA-386.

Fixes: 8b99f4400b69 ("VT-d: fix RMRR related error handling")
Reported-by: Ivan Kardykov <kardykov@tabit.pro>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Ivan Kardykov <kardykov@tabit.pro>
(cherry picked from commit 24ebe875a77833696bbe5c9372e9e1590a7e7101)