conf: use virXMLPropString for actual network parsing

XPath is good for random search of elements, not for accessing
attributes of one node.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>

src/conf/domain_conf.c

@@ -9656,9 +9656,12 @@ virDomainActualNetDefParseXML(xmlNodePtr node,
     }
 
     if (actual->type == VIR_DOMAIN_NET_TYPE_DIRECT) {
-        actual->data.direct.linkdev = virXPathString("string(./source[1]/@dev)", ctxt);
+        xmlNodePtr sourceNode = virXPathNode("./source[1]", ctxt);
 
-        mode = virXPathString("string(./source[1]/@mode)", ctxt);
+        if (sourceNode) {
+            actual->data.direct.linkdev = virXMLPropString(sourceNode, "dev");
+
+            mode = virXMLPropString(sourceNode, "mode");
             if (mode) {
                 int m;
                 if ((m = virNetDevMacVLanModeTypeFromString(mode)) < 0) {
@@ -9669,6 +9672,7 @@ virDomainActualNetDefParseXML(xmlNodePtr node,
                 }
                 actual->data.direct.mode = m;
             }
+        }
     } else if (actual->type == VIR_DOMAIN_NET_TYPE_HOSTDEV) {
         virDomainHostdevDefPtr hostdev = &actual->data.hostdev.def;
 
@@ -9703,7 +9707,9 @@ virDomainActualNetDefParseXML(xmlNodePtr node,
     }
     if (actual->type == VIR_DOMAIN_NET_TYPE_BRIDGE ||
         actual->type == VIR_DOMAIN_NET_TYPE_NETWORK) {
-        char *brname = virXPathString("string(./source/@bridge)", ctxt);
+        xmlNodePtr sourceNode = virXPathNode("./source", ctxt);
+        if (sourceNode) {
+            char *brname = virXMLPropString(sourceNode, "bridge");
 
             if (!brname && actual->type == VIR_DOMAIN_NET_TYPE_BRIDGE) {
                 virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
@@ -9712,7 +9718,7 @@ virDomainActualNetDefParseXML(xmlNodePtr node,
                 goto error;
             }
             actual->data.bridge.brname = brname;
-        macTableManager = virXPathString("string(./source/@macTableManager)", ctxt);
+            macTableManager = virXMLPropString(sourceNode, "macTableManager");
             if (macTableManager &&
                 (actual->data.bridge.macTableManager
                  = virNetworkBridgeMACTableManagerTypeFromString(macTableManager)) <= 0) {
@@ -9723,6 +9729,7 @@ virDomainActualNetDefParseXML(xmlNodePtr node,
                 goto error;
             }
         }
+    }
 
     bandwidth_node = virXPathNode("./bandwidth", ctxt);
     if (bandwidth_node &&