Merge remote-tracking branch 'remotes/otubo/tags/pull-seccomp-20190327' into staging

pull-seccomp-20190327

# gpg: Signature made Wed 27 Mar 2019 12:12:39 GMT
# gpg:                using RSA key DF32E7C0F0FFF9A2
# gpg: Good signature from "Eduardo Otubo (Senior Software Engineer) <otubo@redhat.com>" [full]
# Primary key fingerprint: D67E 1B50 9374 86B4 0723  DBAB DF32 E7C0 F0FF F9A2

* remotes/otubo/tags/pull-seccomp-20190327:
  seccomp: report more useful errors from seccomp
  seccomp: don't kill process for resource control syscalls

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>