Remove the redundant code for attach interface

The 'pci_request_id' attribute of the 'nova.objects.NetworkRequest'
object is already populated by the preceeding call to
'create_resource_requests' [1].

[1] https://opendev.org/openstack/nova/src/tag/22.0.0/nova/network/neutron.py#L2149

Change-Id: I0377d04043130e1acb4f4e8e9b54fbe3ec86e073

Author: dengzhaosen

nova/compute/manager.py

@@ -7763,12 +7763,6 @@ def _attach_interface(self, context, instance, network_id, port_id,
             context, requested_networks, pci_reqs,
             affinity_policy=pci_numa_affinity_policy)
 
-        # We only support one port per attach request so we at most have one
-        # pci request
-        if pci_reqs.requests:
-            pci_req = pci_reqs.requests[0]
-            requested_networks[0].pci_request_id = pci_req.request_id
-
         result = self._allocate_port_resource_for_instance(
             context, instance, pci_reqs, request_groups)
         provider_mappings, resources = result