mtpd: whitelist 'madvise' syscall in seccomp-bpf filter

BUG=chromium:691025
TEST=Verified that mtpd is no longer terminated by minijail0.

Change-Id: I8011cb859ff502e1a133384bbb993588b98d5533
Reviewed-on: https://chromium-review.googlesource.com/440653
Commit-Ready: Ben Chan <benchan@chromium.org>
Tested-by: Ben Chan <benchan@chromium.org>
Reviewed-by: Jorge Lucangeli Obes <jorgelo@chromium.org>
3 files changed