libxtables: prefix - parse and escaped output func

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
diff --git a/extensions/libipt_LOG.c b/extensions/libipt_LOG.c
index aefb54a..23790a0 100644
--- a/extensions/libipt_LOG.c
+++ b/extensions/libipt_LOG.c
@@ -235,7 +235,7 @@
 
 	if (strcmp(loginfo->prefix, "") != 0) {
 		printf("--log-prefix ");
-		save_string(loginfo->prefix);
+		xtables_save_string(loginfo->prefix);
 	}
 
 	if (loginfo->level != LOG_DEFAULT_LEVEL)