util: sysinfo: Convert child buffers to use VIR_BUFFER_INIT_CHILD

Use the new helper to initialize child XML element buffers.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

src/util/virsysinfo.c

@@ -1482,7 +1482,7 @@ int
 virSysinfoFormat(virBufferPtr buf, virSysinfoDefPtr def)
 {
     virBuffer attrBuf = VIR_BUFFER_INITIALIZER;
-    virBuffer childrenBuf = VIR_BUFFER_INITIALIZER;
+    virBuffer childrenBuf = VIR_BUFFER_INIT_CHILD(buf);
     const char *type = virSysinfoTypeToString(def->type);
 
     if (!type) {
@@ -1493,8 +1493,6 @@ virSysinfoFormat(virBufferPtr buf, virSysinfoDefPtr def)
         return -1;
     }
 
-    virBufferSetChildIndent(&childrenBuf, buf);
-
     virSysinfoBIOSFormat(&childrenBuf, def->bios);
     virSysinfoSystemFormat(&childrenBuf, def->system);
     virSysinfoBaseBoardFormat(&childrenBuf, def->baseBoard, def->nbaseBoard);