qemu: monitor: Fix formatting of 'offset' in qemuMonitorJSONSaveMemory

The offset is unsigned long long thus 'U' must be used.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

src/qemu/qemu_monitor_json.c

@@ -3123,7 +3123,7 @@ static int qemuMonitorJSONSaveMemory(qemuMonitorPtr mon,
     int ret = -1;
     virJSONValuePtr cmd = qemuMonitorJSONMakeCommand(cmdtype,
                                                      "U:val", offset,
-                                                     "u:size", length,
+                                                     "U:size", length,
                                                      "s:filename", path,
                                                      NULL);
     virJSONValuePtr reply = NULL;