More LGTM fixups (#1457)

* exclude lib dirs, fix 3 cpp errors

* fix more alerts, exclude mkvparse

Co-authored-by: George Hotz <geohot@gmail.com>
old-commit-hash: e568d3cadc

tools/lib/framereader.py

@@ -1,8 +1,6 @@
 import os
 import sys
-import glob
 import json
-import time
 import struct
 import tempfile
 import threading