Plug a free basic memory leaks

Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/init.c b/init.c
index b26dc9f..fa1df8e 100644
--- a/init.c
+++ b/init.c
@@ -250,6 +250,7 @@
 		free_threads_shm();
 	}
 
+	options_free(fio_options, &def_thread);
 	scleanup();
 }