Fix missing newlines in iptables-save/restore output (Pavol Rusnak <prusnak@suse.cz>)

Bugzilla #568
diff --git a/iptables-save.c b/iptables-save.c
index ee18918..a8a17aa 100644
--- a/iptables-save.c
+++ b/iptables-save.c
@@ -368,7 +368,7 @@
 	}
 
 	if (optind < argc) {
-		fprintf(stderr, "Unknown arguments found on commandline");
+		fprintf(stderr, "Unknown arguments found on commandline\n");
 		exit(1);
 	}