Merge remote-tracking branch 'remotes/rth/tags/pull-rth-20160710' into staging

Merge remote-tracking branch 'remotes/rth/tags/pull-rth-20160710' into staging

build fix for travis

# gpg: Signature made Sun 10 Jul 2016 18:07:02 BST
# gpg:                using RSA key 0xAD1270CC4DD0279B
# gpg: Good signature from "Richard Henderson <rth7680@gmail.com>"
# gpg:                 aka "Richard Henderson <rth@redhat.com>"
# gpg:                 aka "Richard Henderson <rth@twiddle.net>"
# Primary key fingerprint: 9CB1 8DDA F8E8 49AD 2AFC  16A4 AD12 70CC 4DD0 279B

* remotes/rth/tags/pull-rth-20160710:
  build: Use $(AS) for optionrom explicitly
  linux-user: Fix i386 safe-syscall.S

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