conf: disk: Remove one unnecessary level of indentation

Also simplify the code by switching to a for loop.

src/conf/domain_conf.c

@@ -6760,9 +6760,10 @@ virDomainDiskDefParseXML(virDomainXMLOptionPtr xmlopt,
     rawio = virXMLPropString(node, "rawio");
     sgio = virXMLPropString(node, "sgio");
 
-    cur = node->children;
-    while (cur != NULL) {
-        if (cur->type == XML_ELEMENT_NODE) {
+    for (cur = node->children; cur != NULL; cur = cur->next) {
+        if (cur->type != XML_ELEMENT_NODE)
+            continue;
+
         if (!source && xmlStrEqual(cur->name, BAD_CAST "source")) {
             sourceNode = cur;
 
@@ -7176,8 +7177,6 @@ virDomainDiskDefParseXML(virDomainXMLOptionPtr xmlopt,
             /* boot is parsed as part of virDomainDeviceInfoParseXML */
         }
     }
-        cur = cur->next;
-    }
 
     /* Disk volume types will have authentication information handled in
      * virStorageTranslateDiskSourcePool