Remove lint outputs to prevent showing old lint results on error

The lint rules dumped the text output file to stdout on error.  If the
lint binary exited without updating the output file it would show old
results.

Remove the output files before running lint, and only dump the text
output file if it exists.

Bug: 181681346
Test: m lint-check
Change-Id: I4fa962b1212e8715f234912a9a5e049d5c1540e8