Don't block use of USB with containers

virDomainDefCompatibleDevice blocks use of USB if no USB
controller is present. This is not correct for containers
since devices can be assigned directly regardless of any
controllers.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

src/conf/domain_conf.c

@@ -17687,6 +17687,7 @@ virDomainDefCompatibleDevice(virDomainDefPtr def,
                              virDomainDeviceDefPtr dev)
 {
     if (!virDomainDefHasUSB(def) &&
+        STRNEQ(def->os.type, "exe") &&
         virDomainDeviceIsUSB(dev)) {
         virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
                        _("Device configuration is not compatible: "