qemu: fix cleanup of bridge during failure of qemuDomainAttachNetDevice

In qemuDomainAttachNetDevice, the guest's tap interface has only been
attached to the bridge if iface_connected is true. It's possible for
an error to occur prior to that happening, and previously we would
attempt to remove the tap interface from the bridge even if it hadn't
been attached.

src/qemu/qemu_hotplug.c

@@ -837,13 +837,14 @@ cleanup:
                                             net->info.addr.pci.slot) < 0)
             VIR_WARN("Unable to release PCI address on NIC");
 
-        if (iface_connected)
+        if (iface_connected) {
             virDomainConfNWFilterTeardown(net);
 
-        vport = virDomainNetGetActualVirtPortProfile(net);
-        if (vport && vport->virtPortType == VIR_NETDEV_VPORT_PROFILE_OPENVSWITCH)
-            ignore_value(virNetDevOpenvswitchRemovePort(
-                            virDomainNetGetActualBridgeName(net), net->ifname));
+            vport = virDomainNetGetActualVirtPortProfile(net);
+            if (vport && vport->virtPortType == VIR_NETDEV_VPORT_PROFILE_OPENVSWITCH)
+               ignore_value(virNetDevOpenvswitchRemovePort(
+                               virDomainNetGetActualBridgeName(net), net->ifname));
+        }
 
         networkReleaseActualDevice(net);
     }