qemu: add missing break in qemuDomainDeviceCalculatePCIConnectFlags

One of the conditions in qemuDomainDeviceCalculatePCIConnectFlags
was missing a break that could result it in falling through to
an incorrect codepath.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

src/qemu/qemu_domain_address.c

@@ -553,6 +553,7 @@ qemuDomainDeviceCalculatePCIConnectFlags(virDomainDeviceDefPtr dev,
             return pciFlags;
         }
     }
+        break;
 
     case VIR_DOMAIN_DEVICE_FS:
         /* the only type of filesystem so far is virtio-9p-pci */