ApiLint: Performance improvements for verification

Test: tools/apilint/apilint_sha.sh HEAD
Test: python tools/apilint/apilint_test.py
Change-Id: I90f18181cd0d3c43f176d7c9d1b198f6f5172390
(cherry picked from commit 7f8886a9933abbb6f1fdd97d920185b80d439339)
1 file changed