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>
(cherry picked from commit 7a44af96)

src/conf/domain_conf.c

@@ -16996,6 +16996,7 @@ 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: "