Re-enable setting seccomp filters in Minijail.

Now that all the bits have landed, re-enable setting seccomp filters
in Minijail.

BUG=chromium-os:27878
TEST=security_Minijail0
TEST=security_Minijail_seccomp
TEST=platform_CrosDisksArchive

Change-Id: I13aae50a4d172443170e7fbf4bfc84812a424b65
Reviewed-on: https://gerrit.chromium.org/gerrit/21655
Tested-by: Jorge Lucangeli Obes <jorgelo@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Ben Chan <benchan@chromium.org>
Commit-Ready: Jorge Lucangeli Obes <jorgelo@chromium.org>
3 files changed