Fix a bogus warning when parsing <hostdev>

When parsing hostdev, the following message would be emitted:

10:17:19.052: error : virDomainHostdevDefParseXML:3748 : internal error unknown node alias

However, alias is appropriately parsed in
virDomainDeviceInfoParseXML anyway.  Disable the error message
in the initial XML parsing loop.
Signed-off-by: NChris Lalancette <clalance@redhat.com>

src/conf/domain_conf.c

@@ -3716,6 +3716,9 @@ virDomainHostdevDefParseXML(const xmlNodePtr node,
                             goto error;
                 }
             } else if (xmlStrEqual(cur->name, BAD_CAST "address")) {
+                /* address is parsed as part of virDomainDeviceInfoParseXML */
+            } else if (xmlStrEqual(cur->name, BAD_CAST "alias")) {
+                /* alias is parsed as part of virDomainDeviceInfoParseXML */
             } else {
                 virDomainReportError(VIR_ERR_INTERNAL_ERROR,
                                      _("unknown node %s"), cur->name);